QPID-8647: [Broker-J] JUnit 5 tests refactoring for broker-plugins/amqp-1-0-protocol (#185)

diff --git a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/AMQPConnection_1_0ImplTest.java b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/AMQPConnection_1_0ImplTest.java
index 5c6924f..47e4975 100644
--- a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/AMQPConnection_1_0ImplTest.java
+++ b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/AMQPConnection_1_0ImplTest.java
@@ -24,7 +24,7 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.CoreMatchers.is;
 import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.fail;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
@@ -47,7 +47,7 @@
 import org.apache.qpid.server.virtualhost.QueueManagingVirtualHost;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class AMQPConnection_1_0ImplTest extends UnitTestBase
+class AMQPConnection_1_0ImplTest extends UnitTestBase
 {
     private Broker<?> _broker;
     private ServerNetworkConnection _network;
@@ -56,7 +56,7 @@
     private QueueManagingVirtualHost<?> _virtualHost;
 
     @BeforeAll
-    public void setUp() throws Exception
+    void setUp() throws Exception
     {
         _broker = BrokerTestHelper.createBrokerMock();
         final Model model = _broker.getModel();
@@ -72,7 +72,7 @@
     }
 
     @Test
-    public void testGetOpenTransactions()
+    void getOpenTransactions()
     {
         final AMQPConnection_1_0Impl connection =
                 new AMQPConnection_1_0Impl(_broker, _network, _port, Transport.TCP, 0, _aggregateTicket);
@@ -90,7 +90,7 @@
     }
 
     @Test
-    public void testCreateIdentifiedTransaction()
+    void createIdentifiedTransaction()
     {
         final AMQPConnection_1_0Impl connection =
                 new AMQPConnection_1_0Impl(_broker, _network, _port, Transport.TCP, 0, _aggregateTicket);
@@ -105,7 +105,7 @@
     }
 
     @Test
-    public void testGetTransaction()
+    void getTransaction()
     {
         final AMQPConnection_1_0Impl connection =
                 new AMQPConnection_1_0Impl(_broker, _network, _port, Transport.TCP, 0, _aggregateTicket);
@@ -121,26 +121,20 @@
     }
 
     @Test
-    public void testGetTransactionUnknownId()
+    void getTransactionUnknownId()
     {
         final AMQPConnection_1_0Impl connection =
                 new AMQPConnection_1_0Impl(_broker, _network, _port, Transport.TCP, 0, _aggregateTicket);
         connection.setAddressSpace(_virtualHost);
         final IdentifiedTransaction tx1 = connection.createIdentifiedTransaction();
 
-        try
-        {
-            connection.getTransaction(tx1.getId() + 1);
-            fail("UnknownTransactionException is not thrown");
-        }
-        catch (UnknownTransactionException e)
-        {
-            // pass
-        }
+        assertThrows(UnknownTransactionException.class,
+                () -> connection.getTransaction(tx1.getId() + 1),
+                "UnknownTransactionException is not thrown");
     }
 
     @Test
-    public void testRemoveTransaction()
+    void removeTransaction()
     {
         final AMQPConnection_1_0Impl connection =
                 new AMQPConnection_1_0Impl(_broker, _network, _port, Transport.TCP, 0, _aggregateTicket);
@@ -148,19 +142,13 @@
         final IdentifiedTransaction tx1 = connection.createIdentifiedTransaction();
         connection.removeTransaction(tx1.getId());
 
-        try
-        {
-            connection.getTransaction(tx1.getId());
-            fail("UnknownTransactionException is not thrown");
-        }
-        catch (UnknownTransactionException e)
-        {
-            // pass
-        }
+        assertThrows(UnknownTransactionException.class,
+                () -> connection.getTransaction(tx1.getId()),
+                "UnknownTransactionException is not thrown");
     }
 
     @Test
-    public void resetStatistics()
+    void resetStatistics()
     {
         final AMQPConnection_1_0Impl connection =
                 new AMQPConnection_1_0Impl(_broker, _network, _port, Transport.TCP, 0, _aggregateTicket);
diff --git a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/ConsumerTarget_1_0Test.java b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/ConsumerTarget_1_0Test.java
index 8483f5d..7aafaf0 100644
--- a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/ConsumerTarget_1_0Test.java
+++ b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/ConsumerTarget_1_0Test.java
@@ -32,8 +32,8 @@
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
-import java.util.Collections;
 import java.util.List;
+import java.util.Map;
 import java.util.concurrent.atomic.AtomicReference;
 
 import org.junit.jupiter.api.BeforeAll;
@@ -62,19 +62,21 @@
 import org.apache.qpid.server.store.StoredMessage;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class ConsumerTarget_1_0Test extends UnitTestBase
+@SuppressWarnings({"rawtypes", "unchecked"})
+class ConsumerTarget_1_0Test extends UnitTestBase
 {
-    private final AMQPDescribedTypeRegistry _describedTypeRegistry = AMQPDescribedTypeRegistry.newInstance()
-                                                                                              .registerTransportLayer()
-                                                                                              .registerMessagingLayer()
-                                                                                              .registerTransactionLayer()
-                                                                                              .registerSecurityLayer()
-                                                                                              .registerExtensionSoleconnLayer();
+    private static final AMQPDescribedTypeRegistry AMQP_DESCRIBED_TYPE_REGISTRY = AMQPDescribedTypeRegistry.newInstance()
+            .registerTransportLayer()
+            .registerMessagingLayer()
+            .registerTransactionLayer()
+            .registerSecurityLayer()
+            .registerExtensionSoleconnLayer();
+
     private ConsumerTarget_1_0 _consumerTarget;
     private SendingLinkEndpoint _sendingLinkEndpoint;
 
     @BeforeAll
-    public void setUp() throws Exception
+    void setUp()
     {
         final AMQPConnection_1_0 connection = mock(AMQPConnection_1_0.class);
         final Session_1_0 session = mock(Session_1_0.class);
@@ -83,19 +85,19 @@
         when(_sendingLinkEndpoint.isAttached()).thenReturn(true);
         when(session.getAMQPConnection()).thenReturn(connection);
         when(session.getConnection()).thenReturn(connection);
-        when(connection.getDescribedTypeRegistry()).thenReturn(_describedTypeRegistry);
+        when(connection.getDescribedTypeRegistry()).thenReturn(AMQP_DESCRIBED_TYPE_REGISTRY);
         when(connection.getContextValue(Long.class, Consumer.SUSPEND_NOTIFICATION_PERIOD)).thenReturn(10000L);
 
         _consumerTarget = new ConsumerTarget_1_0(_sendingLinkEndpoint, true);
     }
 
     @Test
-    public void testTTLAdjustedOnSend() throws Exception
+    void TTLAdjustedOnSend() throws Exception
     {
-        final MessageInstanceConsumer comsumer = mock(MessageInstanceConsumer.class);
+        final MessageInstanceConsumer consumer = mock(MessageInstanceConsumer.class);
 
-        long ttl = 2000L;
-        long arrivalTime = System.currentTimeMillis() - 1000L;
+        final long ttl = 2000L;
+        final long arrivalTime = System.currentTimeMillis() - 1000L;
 
         final Header header = new Header();
         header.setTtl(UnsignedInteger.valueOf(ttl));
@@ -103,30 +105,30 @@
         final MessageInstance messageInstance = mock(MessageInstance.class);
         when(messageInstance.getMessage()).thenReturn(message);
 
-        AtomicReference<QpidByteBuffer> payloadRef = new AtomicReference<>();
+        final AtomicReference<QpidByteBuffer> payloadRef = new AtomicReference<>();
         doAnswer(invocation ->
-                 {
-                     final Object[] args = invocation.getArguments();
-                     Transfer transfer = (Transfer) args[0];
+        {
+            final Object[] args = invocation.getArguments();
+            final Transfer transfer = (Transfer) args[0];
 
-                     QpidByteBuffer transferPayload = transfer.getPayload();
+            final QpidByteBuffer transferPayload = transfer.getPayload();
 
-                     QpidByteBuffer payloadCopy = transferPayload.duplicate();
-                     payloadRef.set(payloadCopy);
-                     return null;
-                 }).when(_sendingLinkEndpoint).transfer(any(Transfer.class), anyBoolean());
+            final QpidByteBuffer payloadCopy = transferPayload.duplicate();
+            payloadRef.set(payloadCopy);
+            return null;
+        }).when(_sendingLinkEndpoint).transfer(any(Transfer.class), anyBoolean());
 
-        _consumerTarget.doSend(comsumer, messageInstance, false);
+        _consumerTarget.doSend(consumer, messageInstance, false);
 
         verify(_sendingLinkEndpoint, times(1)).transfer(any(Transfer.class), anyBoolean());
 
         final List<EncodingRetainingSection<?>> sections;
-        try (QpidByteBuffer payload = payloadRef.get())
+        try (final QpidByteBuffer payload = payloadRef.get())
         {
-            sections = new SectionDecoderImpl(_describedTypeRegistry.getSectionDecoderRegistry()).parseAll(payload);
+            sections = new SectionDecoderImpl(AMQP_DESCRIBED_TYPE_REGISTRY.getSectionDecoderRegistry()).parseAll(payload);
         }
         Header sentHeader = null;
-        for (EncodingRetainingSection<?> section : sections)
+        for (final EncodingRetainingSection<?> section : sections)
         {
             if (section instanceof HeaderSection)
             {
@@ -141,21 +143,21 @@
 
     private Message_1_0 createTestMessage(final Header header, long arrivalTime)
     {
-        DeliveryAnnotationsSection deliveryAnnotations =
-                new DeliveryAnnotations(Collections.emptyMap()).createEncodingRetainingSection();
-        MessageAnnotationsSection messageAnnotations =
-                new MessageAnnotations(Collections.emptyMap()).createEncodingRetainingSection();
-        ApplicationPropertiesSection applicationProperties =
-                new ApplicationProperties(Collections.emptyMap()).createEncodingRetainingSection();
-        FooterSection footer = new Footer(Collections.emptyMap()).createEncodingRetainingSection();
-        MessageMetaData_1_0 metaData = new MessageMetaData_1_0(header.createEncodingRetainingSection(),
-                                                               deliveryAnnotations,
-                                                               messageAnnotations,
-                                                               new Properties().createEncodingRetainingSection(),
-                                                               applicationProperties,
-                                                               footer,
-                                                               arrivalTime,
-                                                               0);
+        final DeliveryAnnotationsSection deliveryAnnotations =
+                new DeliveryAnnotations(Map.of()).createEncodingRetainingSection();
+        final MessageAnnotationsSection messageAnnotations =
+                new MessageAnnotations(Map.of()).createEncodingRetainingSection();
+        final ApplicationPropertiesSection applicationProperties =
+                new ApplicationProperties(Map.of()).createEncodingRetainingSection();
+        final FooterSection footer = new Footer(Map.of()).createEncodingRetainingSection();
+        final MessageMetaData_1_0 metaData = new MessageMetaData_1_0(header.createEncodingRetainingSection(),
+                deliveryAnnotations,
+                messageAnnotations,
+                new Properties().createEncodingRetainingSection(),
+                applicationProperties,
+                footer,
+                arrivalTime,
+                0);
 
         final StoredMessage<MessageMetaData_1_0> storedMessage = mock(StoredMessage.class);
         when(storedMessage.getContent(eq(0), anyInt())).thenReturn(QpidByteBuffer.emptyQpidByteBuffer());
diff --git a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/LinkImplTest.java b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/LinkImplTest.java
index b365b29..8312c91 100644
--- a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/LinkImplTest.java
+++ b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/LinkImplTest.java
@@ -53,7 +53,7 @@
 import org.apache.qpid.server.transport.AMQPConnection;
 
 @SuppressWarnings({"rawtypes", "unchecked"})
-public class LinkImplTest
+class LinkImplTest
 {
     private final static String REMOTE_CONTAINER_ID = "remote-container-id";
     private final static String LINK_NAME = "link-name";
@@ -61,13 +61,13 @@
     private LinkRegistry<Source, Target> _linkRegistry;
 
     @BeforeEach
-    public void setUp()
+    void setUp()
     {
         _linkRegistry = mock(LinkRegistry.class);
     }
 
     @Test
-    public void linkStealing_PublishToQueue() throws Exception
+    void linkStealing_PublishToQueue() throws Exception
     {
         final Queue<?> queue = mock(Queue.class);
         final Session_1_0 session1 = createSession("principal1", queue);
@@ -87,7 +87,7 @@
     }
 
     @Test
-    public void linkStealing_ConsumeQueue() throws Exception
+    void linkStealing_ConsumeQueue() throws Exception
     {
         final Queue<?> queue = mock(Queue.class);
         final Session_1_0 session1 = createSession("principal1", queue);
@@ -107,7 +107,7 @@
     }
 
     @Test
-    public void linkStealing_PublishToExchange() throws Exception
+    void linkStealing_PublishToExchange() throws Exception
     {
         final Exchange<?> exchange = mock(Exchange.class);
         final Queue<?> queue = mock(Queue.class);
@@ -128,7 +128,7 @@
     }
 
     @Test
-    public void linkStealing_ConsumeExchange() throws Exception
+    void linkStealing_ConsumeExchange() throws Exception
     {
         final Exchange<?> exchange = mock(Exchange.class);
         final Queue<?> queue = mock(Queue.class);
diff --git a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/LinkRegistryTest.java b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/LinkRegistryTest.java
index 180a107..c030cb8 100644
--- a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/LinkRegistryTest.java
+++ b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/LinkRegistryTest.java
@@ -37,142 +37,141 @@
 import org.apache.qpid.server.virtualhost.QueueManagingVirtualHost;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class LinkRegistryTest extends UnitTestBase
+class LinkRegistryTest extends UnitTestBase
 {
-    public static final Pattern ANY = Pattern.compile(".*");
-    private QueueManagingVirtualHost _virtualHost;
-    private LinkRegistryImpl _linkRegistry;
+    static final Pattern ANY = Pattern.compile(".*");
+
+    private QueueManagingVirtualHost<?> _virtualHost;
+    private LinkRegistryImpl<?, ?> _linkRegistry;
 
     @BeforeAll
-    public void beforeAll()
+    void beforeAll()
     {
         _virtualHost = mock(QueueManagingVirtualHost.class);
     }
 
     @BeforeEach
-    public void beforeEach()
+    void beforeEach()
     {
-        _linkRegistry = new LinkRegistryImpl(_virtualHost);
+        _linkRegistry = new LinkRegistryImpl<>(_virtualHost);
     }
 
     @Test
-    public void testGetSendingLink()
+    void getSendingLink()
     {
-        String remoteContainerId = "testRemoteContainerId";
-        String linkName = "testLinkName";
-        LinkModel link = _linkRegistry.getSendingLink(remoteContainerId, linkName);
+        final String remoteContainerId = "testRemoteContainerId";
+        final String linkName = "testLinkName";
+        final LinkModel link = _linkRegistry.getSendingLink(remoteContainerId, linkName);
         assertNotNull(link, "LinkRegistryModel#getSendingLink should always return an object");
-        LinkModel link2 = _linkRegistry.getSendingLink(remoteContainerId, linkName);
+        final LinkModel link2 = _linkRegistry.getSendingLink(remoteContainerId, linkName);
         assertNotNull(link2, "LinkRegistryModel#getSendingLink should always return an object");
         assertSame(link, link2, "Two calls to LinkRegistryModel#getSendingLink should return the same object");
     }
 
     @Test
-    public void testGetReceivingLink()
+    void getReceivingLink()
     {
-        String remoteContainerId = "testRemoteContainerId";
-        String linkName = "testLinkName";
-        LinkModel link = _linkRegistry.getReceivingLink(remoteContainerId, linkName);
+        final String remoteContainerId = "testRemoteContainerId";
+        final String linkName = "testLinkName";
+        final LinkModel link = _linkRegistry.getReceivingLink(remoteContainerId, linkName);
         assertNotNull(link, "LinkRegistryModel#getReceivingLink should always return an object");
-        LinkModel link2 = _linkRegistry.getReceivingLink(remoteContainerId, linkName);
+        final LinkModel link2 = _linkRegistry.getReceivingLink(remoteContainerId, linkName);
         assertNotNull(link2, "LinkRegistryModel#getReceivingLink should always return an object");
-        assertSame(link,
-                              link2,
-                              "Two calls to LinkRegistryModel#getReceivingLink should return the same object");
+        assertSame(link, link2, "Two calls to LinkRegistryModel#getReceivingLink should return the same object");
     }
 
     @Test
-    public void testPurgeSendingLinksFromRegistryWithEmptyRegistry()
+    void purgeSendingLinksFromRegistryWithEmptyRegistry()
     {
         _linkRegistry.purgeSendingLinks(ANY, ANY);
     }
 
     @Test
-    public void testPurgeSendingLinksExactMatch()
+    void purgeSendingLinksExactMatch()
     {
         _linkRegistry.getSendingLink("testContainerId", "testLinkName");
         _linkRegistry.purgeSendingLinks(Pattern.compile("testContainerId"), Pattern.compile("testLinkName"));
-        LinkRegistryImpl.LinkRegistryDump dump = _linkRegistry.dump();
+        final LinkRegistryImpl.LinkRegistryDump dump = _linkRegistry.dump();
         assertEquals(dump.getContainers().size(), (long) 0);
     }
 
     @Test
-    public void testPurgeSendingLinksRegEx()
+    void purgeSendingLinksRegEx()
     {
         _linkRegistry.getSendingLink("testContainerId", "testLinkName");
         _linkRegistry.purgeSendingLinks(Pattern.compile("test.*Id"), Pattern.compile("testLink.*"));
-        LinkRegistryImpl.LinkRegistryDump dump = _linkRegistry.dump();
+        final LinkRegistryImpl.LinkRegistryDump dump = _linkRegistry.dump();
         assertEquals(dump.getContainers().size(), (long) 0);
     }
 
     @Test
-    public void testPurgeSendingLinksNotMatchingRegEx()
+    void purgeSendingLinksNotMatchingRegEx()
     {
         _linkRegistry.getSendingLink("testContainerId", "testLinkName");
         _linkRegistry.purgeSendingLinks(Pattern.compile("Foo.*"), Pattern.compile(".*bar"));
-        LinkRegistryImpl.LinkRegistryDump dump = _linkRegistry.dump();
+        final LinkRegistryImpl.LinkRegistryDump dump = _linkRegistry.dump();
         assertEquals(dump.getContainers().size(), (long) 1);
     }
 
     @Test
-    public void testPurgeSendingLinksDoesNotRemoveReceivingLink()
+    void purgeSendingLinksDoesNotRemoveReceivingLink()
     {
         _linkRegistry.getSendingLink("testContainerId", "testLinkName");
         _linkRegistry.getReceivingLink("testContainerId", "testLinkName");
         _linkRegistry.purgeSendingLinks(Pattern.compile("testContainerId"), Pattern.compile("testLinkName"));
-        LinkRegistryImpl.LinkRegistryDump dump = _linkRegistry.dump();
+        final LinkRegistryImpl.LinkRegistryDump dump = _linkRegistry.dump();
         assertEquals(dump.getContainers().size(), (long) 1);
         assertEquals(dump.getContainers().get("testContainerId").getReceivingLinks().size(), (long) 1);
         assertEquals(dump.getContainers().get("testContainerId").getSendingLinks().size(), (long) 0);
     }
 
     @Test
-    public void testPurgeReceivingLinksFromRegistryWithEmptyRegistry()
+    void purgeReceivingLinksFromRegistryWithEmptyRegistry()
     {
         _linkRegistry.purgeReceivingLinks(ANY, ANY);
     }
 
     @Test
-    public void testPurgeReceivingLinksExactMatch()
+    void purgeReceivingLinksExactMatch()
     {
         _linkRegistry.getReceivingLink("testContainerId", "testLinkName");
         _linkRegistry.purgeReceivingLinks(Pattern.compile("testContainerId"), Pattern.compile("testLinkName"));
-        LinkRegistryImpl.LinkRegistryDump dump = _linkRegistry.dump();
+        final LinkRegistryImpl.LinkRegistryDump dump = _linkRegistry.dump();
         assertEquals(dump.getContainers().size(), (long) 0);
     }
 
     @Test
-    public void testPurgeReceivingLinksRegEx()
+    void purgeReceivingLinksRegEx()
     {
         _linkRegistry.getReceivingLink("testContainerId", "testLinkName");
         _linkRegistry.purgeReceivingLinks(Pattern.compile("test.*Id"), Pattern.compile("testLink.*"));
-        LinkRegistryImpl.LinkRegistryDump dump = _linkRegistry.dump();
+        final LinkRegistryImpl.LinkRegistryDump dump = _linkRegistry.dump();
         assertEquals(dump.getContainers().size(), (long) 0);
     }
 
     @Test
-    public void testPurgeReceivingLinksNotMatchingRegEx()
+    void purgeReceivingLinksNotMatchingRegEx()
     {
         _linkRegistry.getReceivingLink("testContainerId", "testLinkName");
         _linkRegistry.purgeReceivingLinks(Pattern.compile("Foo.*"), Pattern.compile(".*bar"));
-        LinkRegistryImpl.LinkRegistryDump dump = _linkRegistry.dump();
+        final LinkRegistryImpl.LinkRegistryDump dump = _linkRegistry.dump();
         assertEquals(dump.getContainers().size(), (long) 1);
     }
 
     @Test
-    public void testPurgeReceivingLinksDoesNotRemoveSendingLink()
+    void purgeReceivingLinksDoesNotRemoveSendingLink()
     {
         _linkRegistry.getSendingLink("testContainerId", "testLinkName");
         _linkRegistry.getReceivingLink("testContainerId", "testLinkName");
         _linkRegistry.purgeReceivingLinks(Pattern.compile("testContainerId"), Pattern.compile("testLinkName"));
-        LinkRegistryImpl.LinkRegistryDump dump = _linkRegistry.dump();
+        final LinkRegistryImpl.LinkRegistryDump dump = _linkRegistry.dump();
         assertEquals(dump.getContainers().size(), (long) 1);
         assertEquals(dump.getContainers().get("testContainerId").getReceivingLinks().size(), (long) 0);
         assertEquals(dump.getContainers().get("testContainerId").getSendingLinks().size(), (long) 1);
     }
 
     @Test
-    public void testDump()
+    void dump()
     {
         _linkRegistry.getSendingLink("testContainerId1", "testLinkName");
         _linkRegistry.getReceivingLink("testContainerId2", "testLinkName");
@@ -206,7 +205,7 @@
     }
 
     @Test
-    public void testDumpIsSerializable() throws Exception
+    void dumpIsSerializable() throws Exception
     {
         _linkRegistry.getSendingLink("testContainerId1", "testLinkName");
         _linkRegistry.getReceivingLink("testContainerId2", "testLinkName");
@@ -216,5 +215,4 @@
 
         assertNotNull(data);
     }
-
 }
diff --git a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/MessageConverter_Internal_to_1_0Test.java b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/MessageConverter_Internal_to_1_0Test.java
index f97bb19..6c3f24b 100644
--- a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/MessageConverter_Internal_to_1_0Test.java
+++ b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/MessageConverter_Internal_to_1_0Test.java
@@ -31,7 +31,6 @@
 import java.io.ObjectOutputStream;
 import java.io.Serializable;
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -63,23 +62,23 @@
 import org.apache.qpid.server.store.StoredMessage;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class MessageConverter_Internal_to_1_0Test extends UnitTestBase
+class MessageConverter_Internal_to_1_0Test extends UnitTestBase
 {
-    private final MessageConverter_Internal_to_v1_0 _converter = new MessageConverter_Internal_to_v1_0();
-    private final AMQPDescribedTypeRegistry _typeRegistry = AMQPDescribedTypeRegistry.newInstance()
-                                                                                     .registerTransportLayer()
-                                                                                     .registerMessagingLayer()
-                                                                                     .registerTransactionLayer()
-                                                                                     .registerSecurityLayer();
+    private static final MessageConverter_Internal_to_v1_0 CONVERTER = new MessageConverter_Internal_to_v1_0();
+    private static final AMQPDescribedTypeRegistry TYPE_REGISTRY = AMQPDescribedTypeRegistry.newInstance()
+            .registerTransportLayer()
+            .registerMessagingLayer()
+            .registerTransactionLayer()
+            .registerSecurityLayer();
 
-    private final StoredMessage<InternalMessageMetaData> _handle = mock(StoredMessage.class);
+    private static final StoredMessage<InternalMessageMetaData> HANDLE = mock(StoredMessage.class);
 
-    private final AMQMessageHeader _amqpHeader = mock(AMQMessageHeader.class);
+    private static final AMQMessageHeader AMQP_HEADER = mock(AMQMessageHeader.class);
 
     @Test
-    public void testStringMessage() throws Exception
+    void stringMessage() throws Exception
     {
-        String content = "testContent";
+        final String content = "testContent";
         final String mimeType = "text/plain";
         doTest(content,
                mimeType,
@@ -90,9 +89,9 @@
     }
 
     @Test
-    public void testStringMessageWithUnknownMimeType() throws Exception
+    void stringMessageWithUnknownMimeType() throws Exception
     {
-        String content = "testContent";
+        final String content = "testContent";
         final String mimeType = "foo/bar";
         doTest(content,
                mimeType,
@@ -103,9 +102,9 @@
     }
 
     @Test
-    public void testStringMessageWithoutMimeType() throws Exception
+    void stringMessageWithoutMimeType() throws Exception
     {
-        String content = "testContent";
+        final String content = "testContent";
         doTest(content,
                null,
                AmqpValueSection.class,
@@ -115,9 +114,9 @@
     }
 
     @Test
-    public void testListMessageWithMimeType() throws Exception
+    void listMessageWithMimeType() throws Exception
     {
-        ArrayList<?> content = Lists.newArrayList("testItem", 37.5, 42);
+        final ArrayList<?> content = Lists.newArrayList("testItem", 37.5, 42);
         doTest(content,
                "text/plain",
                AmqpSequenceSection.class,
@@ -127,9 +126,9 @@
     }
 
     @Test
-    public void testListMessageWithoutMimeType() throws Exception
+    void listMessageWithoutMimeType() throws Exception
     {
-        ArrayList<?> content = Lists.newArrayList("testItem", 37.5, 42);
+        final ArrayList<?> content = Lists.newArrayList("testItem", 37.5, 42);
         doTest(content,
                null,
                AmqpSequenceSection.class,
@@ -139,9 +138,9 @@
     }
 
     @Test
-    public void testListMessageWithoutMimeTypeWithNonJmsContent() throws Exception
+    void listMessageWithoutMimeTypeWithNonJmsContent() throws Exception
     {
-        ArrayList<?> content = Lists.newArrayList("testItem", 37.5, 42, Lists.newArrayList());
+        final ArrayList<?> content = Lists.newArrayList("testItem", 37.5, 42, Lists.newArrayList());
         doTest(content,
                null,
                AmqpSequenceSection.class,
@@ -151,9 +150,9 @@
     }
 
     @Test
-    public void testByteArrayMessageWithoutMimeType() throws Exception
+    void byteArrayMessageWithoutMimeType() throws Exception
     {
-        byte[] content = "testContent".getBytes(UTF_8);
+        final byte[] content = "testContent".getBytes(UTF_8);
         doTest(content,
                null,
                DataSection.class,
@@ -163,9 +162,9 @@
     }
 
     @Test
-    public void testByteArrayMessageWithMimeType() throws Exception
+    void byteArrayMessageWithMimeType() throws Exception
     {
-        byte[] content = "testContent".getBytes(UTF_8);
+        final byte[] content = "testContent".getBytes(UTF_8);
         final String mimeType = "foo/bar";
         doTest(content,
                mimeType,
@@ -176,9 +175,9 @@
     }
 
     @Test
-    public void testEmptyByteArrayMessageWithMimeType() throws Exception
+    void emptyByteArrayMessageWithMimeType() throws Exception
     {
-        byte[] content = new byte[0];
+        final byte[] content = new byte[0];
         final String mimeType = "foo/bar";
         doTest(content,
                mimeType,
@@ -189,9 +188,9 @@
     }
 
     @Test
-    public void testMapMessageWithMimeType() throws Exception
+    void mapMessageWithMimeType() throws Exception
     {
-        HashMap<Object, Object> content = new HashMap<>();
+        final HashMap<Object, Object> content = new HashMap<>();
         content.put("key1", 37);
         content.put("key2", "foo");
         final String mimeType = "foo/bar";
@@ -204,9 +203,9 @@
     }
 
     @Test
-    public void testMapMessageWithoutMimeType() throws Exception
+    void mapMessageWithoutMimeType() throws Exception
     {
-        HashMap<Object, Object> content = new HashMap<>();
+        final HashMap<Object, Object> content = new HashMap<>();
         content.put("key1", 37);
         content.put("key2", "foo");
         doTest(content,
@@ -218,10 +217,10 @@
     }
 
     @Test
-    public void testMapMessageWithMimeTypeWithNonJmsContent() throws Exception
+    void mapMessageWithMimeTypeWithNonJmsContent() throws Exception
     {
-        HashMap<Object, Object> content = new HashMap<>();
-        content.put(37, Collections.singletonMap("foo", "bar"));
+        final HashMap<Object, Object> content = new HashMap<>();
+        content.put(37, Map.of("foo", "bar"));
         final String mimeType = "foo/bar";
         doTest(content,
                mimeType,
@@ -232,9 +231,9 @@
     }
 
     @Test
-    public void testSerializableMessageWithMimeType() throws Exception
+    void serializableMessageWithMimeType() throws Exception
     {
-        Serializable content = new MySerializable();
+        final Serializable content = new MySerializable();
         final String mimeType = "foo/bar";
         doTest(content,
                mimeType,
@@ -245,9 +244,9 @@
     }
 
     @Test
-    public void testSerializableMessageWithoutMimeType() throws Exception
+    void serializableMessageWithoutMimeType() throws Exception
     {
-        Serializable content = new MySerializable();
+        final Serializable content = new MySerializable();
         doTest(content,
                null,
                DataSection.class,
@@ -257,7 +256,7 @@
     }
 
     @Test
-    public void testNullMessageWithoutMimeType() throws Exception
+    void nullMessageWithoutMimeType() throws Exception
     {
         doTest(null,
                null,
@@ -268,9 +267,9 @@
     }
 
     @Test
-    public void testUuidMessageWithMimeType() throws Exception
+    void uuidMessageWithMimeType() throws Exception
     {
-        UUID content = UUID.randomUUID();
+        final UUID content = UUID.randomUUID();
         final String mimeType = "foo/bar";
         doTest(content,
                mimeType,
@@ -280,12 +279,10 @@
                null);
     }
 
-
-
     private byte[] getObjectStreamMessageBytes(final Serializable o) throws Exception
     {
-        try (ByteArrayOutputStream bos = new ByteArrayOutputStream();
-             ObjectOutputStream oos = new ObjectOutputStream(bos))
+        try (final ByteArrayOutputStream bos = new ByteArrayOutputStream();
+             final ObjectOutputStream oos = new ObjectOutputStream(bos))
         {
             oos.writeObject(o);
             return bos.toByteArray();
@@ -296,31 +293,30 @@
                                                                            final int expectedNumberOfSections)
             throws Exception
     {
-        SectionDecoder sectionDecoder = new SectionDecoderImpl(_typeRegistry.getSectionDecoderRegistry());
+        final SectionDecoder sectionDecoder = new SectionDecoderImpl(TYPE_REGISTRY.getSectionDecoderRegistry());
         final List<EncodingRetainingSection<?>> sections = sectionDecoder.parseAll(content);
         assertEquals(expectedNumberOfSections, (long) sections.size(), "Unexpected number of sections");
         return sections;
     }
 
-
     protected InternalMessage getAmqMessage(final Serializable content, final String mimeType) throws Exception
     {
         final byte[] serializedContent = getObjectStreamMessageBytes(content);
         configureMessageContent(serializedContent);
         configureMessageHeader(mimeType);
 
-        final InternalMessageHeader internalMessageHeader = new InternalMessageHeader(_amqpHeader);
+        final InternalMessageHeader internalMessageHeader = new InternalMessageHeader(AMQP_HEADER);
         final int contentSize = serializedContent == null ? 0 : serializedContent.length;
         final InternalMessageMetaData metaData =
                 new InternalMessageMetaData(false, internalMessageHeader, contentSize);
-        when(_handle.getMetaData()).thenReturn(metaData);
+        when(HANDLE.getMetaData()).thenReturn(metaData);
 
-        return ((InternalMessage) InternalMessageMetaDataType.INSTANCE.createMessage(_handle));
+        return ((InternalMessage) InternalMessageMetaDataType.INSTANCE.createMessage(HANDLE));
     }
 
     private void configureMessageHeader(final String mimeType)
     {
-        when(_amqpHeader.getMimeType()).thenReturn(mimeType);
+        when(AMQP_HEADER.getMimeType()).thenReturn(mimeType);
     }
 
     private void configureMessageContent(byte[] section)
@@ -330,24 +326,23 @@
             section = new byte[0];
         }
         final QpidByteBuffer combined = QpidByteBuffer.wrap(section);
-        when(_handle.getContentSize()).thenReturn(section.length);
+        when(HANDLE.getContentSize()).thenReturn(section.length);
         final ArgumentCaptor<Integer> offsetCaptor = ArgumentCaptor.forClass(Integer.class);
         final ArgumentCaptor<Integer> sizeCaptor = ArgumentCaptor.forClass(Integer.class);
 
-        when(_handle.getContent(offsetCaptor.capture(),
-                                sizeCaptor.capture())).then(invocation -> combined.view(offsetCaptor.getValue(),
-                                                                                        sizeCaptor.getValue()));
+        when(HANDLE.getContent(offsetCaptor.capture(), sizeCaptor.capture()))
+                .then(invocation -> combined.view(offsetCaptor.getValue(), sizeCaptor.getValue()));
     }
 
     private Byte getJmsMessageTypeAnnotation(final Message_1_0 convertedMessage)
     {
-        MessageAnnotationsSection messageAnnotationsSection = convertedMessage.getMessageAnnotationsSection();
+        final MessageAnnotationsSection messageAnnotationsSection = convertedMessage.getMessageAnnotationsSection();
         if (messageAnnotationsSection != null)
         {
-            Map<Symbol, Object> messageAnnotations = messageAnnotationsSection.getValue();
+            final Map<Symbol, Object> messageAnnotations = messageAnnotationsSection.getValue();
             if (messageAnnotations != null)
             {
-                Object annotation = messageAnnotations.get(Symbol.valueOf("x-opt-jms-msg-type"));
+                final Object annotation = messageAnnotations.get(Symbol.valueOf("x-opt-jms-msg-type"));
                 if (annotation instanceof Byte)
                 {
                     return ((Byte) annotation);
@@ -365,25 +360,24 @@
                         final Byte expectedJmsTypeAnnotation) throws Exception
     {
         final InternalMessage sourceMessage = getAmqMessage(messageBytes, mimeType);
-        final Message_1_0 convertedMessage = _converter.convert(sourceMessage, mock(NamedAddressSpace.class));
+        final Message_1_0 convertedMessage = CONVERTER.convert(sourceMessage, mock(NamedAddressSpace.class));
         final QpidByteBuffer content = convertedMessage.getContent();
 
-        List<EncodingRetainingSection<?>> sections = getEncodingRetainingSections(content, 1);
-        EncodingRetainingSection<?> encodingRetainingSection = sections.get(0);
+        final List<EncodingRetainingSection<?>> sections = getEncodingRetainingSections(content, 1);
+        final EncodingRetainingSection<?> encodingRetainingSection = sections.get(0);
         assertEquals(expectedBodySection, encodingRetainingSection.getClass(), "Unexpected section type");
 
         if (expectedContent instanceof byte[])
         {
-            assertArrayEquals(((byte[]) expectedContent),
-                                         ((Binary) encodingRetainingSection.getValue()).getArray(),
-                                         "Unexpected content");
+            assertArrayEquals(((byte[]) expectedContent), ((Binary) encodingRetainingSection.getValue()).getArray(),
+                    "Unexpected content");
         }
         else
         {
             assertEquals(expectedContent, encodingRetainingSection.getValue(), "Unexpected content");
         }
 
-        Symbol contentType = getContentType(convertedMessage);
+        final Symbol contentType = getContentType(convertedMessage);
         if (expectedContentType == null)
         {
             assertNull(contentType, "Content type should be null");
@@ -393,7 +387,7 @@
             assertEquals(expectedContentType, contentType, "Unexpected content type");
         }
 
-        Byte jmsMessageTypeAnnotation = getJmsMessageTypeAnnotation(convertedMessage);
+        final Byte jmsMessageTypeAnnotation = getJmsMessageTypeAnnotation(convertedMessage);
         if (expectedJmsTypeAnnotation == null)
         {
             assertNull(jmsMessageTypeAnnotation, "Unexpected annotation 'x-opt-jms-msg-type'");
diff --git a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/MessageConverter_v1_0_to_InternalTest.java b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/MessageConverter_v1_0_to_InternalTest.java
index cc65542..27b6b12 100644
--- a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/MessageConverter_v1_0_to_InternalTest.java
+++ b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/MessageConverter_v1_0_to_InternalTest.java
@@ -31,7 +31,6 @@
 import java.io.IOException;
 import java.io.ObjectOutputStream;
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.LinkedHashMap;
@@ -62,34 +61,34 @@
 import org.apache.qpid.server.store.StoredMessage;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class MessageConverter_v1_0_to_InternalTest extends UnitTestBase
+class MessageConverter_v1_0_to_InternalTest extends UnitTestBase
 {
     private static final MessageAnnotations MESSAGE_MESSAGE_ANNOTATION =
-            new MessageAnnotations(Collections.singletonMap(Symbol.valueOf("x-opt-jms-msg-type"), (byte) 0));
+            new MessageAnnotations(Map.of(Symbol.valueOf("x-opt-jms-msg-type"), (byte) 0));
     private static final MessageAnnotations OBJECT_MESSAGE_MESSAGE_ANNOTATION =
-            new MessageAnnotations(Collections.singletonMap(Symbol.valueOf("x-opt-jms-msg-type"), (byte) 1));
+            new MessageAnnotations(Map.of(Symbol.valueOf("x-opt-jms-msg-type"), (byte) 1));
     private static final MessageAnnotations MAP_MESSAGE_MESSAGE_ANNOTATION =
-            new MessageAnnotations(Collections.singletonMap(Symbol.valueOf("x-opt-jms-msg-type"), (byte) 2));
+            new MessageAnnotations(Map.of(Symbol.valueOf("x-opt-jms-msg-type"), (byte) 2));
     private static final MessageAnnotations BYTE_MESSAGE_MESSAGE_ANNOTATION =
-            new MessageAnnotations(Collections.singletonMap(Symbol.valueOf("x-opt-jms-msg-type"), (byte) 3));
+            new MessageAnnotations(Map.of(Symbol.valueOf("x-opt-jms-msg-type"), (byte) 3));
     private static final MessageAnnotations STREAM_MESSAGE_MESSAGE_ANNOTATION =
-            new MessageAnnotations(Collections.singletonMap(Symbol.valueOf("x-opt-jms-msg-type"), (byte) 4));
+            new MessageAnnotations(Map.of(Symbol.valueOf("x-opt-jms-msg-type"), (byte) 4));
     private static final MessageAnnotations TEXT_MESSAGE_MESSAGE_ANNOTATION =
-            new MessageAnnotations(Collections.singletonMap(Symbol.valueOf("x-opt-jms-msg-type"), (byte) 5));
+            new MessageAnnotations(Map.of(Symbol.valueOf("x-opt-jms-msg-type"), (byte) 5));
     private MessageConverter_v1_0_to_Internal _converter;
 
     @BeforeAll
-    public void setUp() throws Exception
+    void setUp()
     {
         _converter = new MessageConverter_v1_0_to_Internal();
     }
 
     @Test
-    public void testAmqpValueWithNullWithTextMessageAnnotation()
+    void amqpValueWithNullWithTextMessageAnnotation()
     {
         final Object expected = null;
         final AmqpValue amqpValue = new AmqpValue(expected);
-        Message_1_0 sourceMessage =
+        final Message_1_0 sourceMessage =
                 createTestMessage(TEXT_MESSAGE_MESSAGE_ANNOTATION, amqpValue.createEncodingRetainingSection());
 
         final InternalMessage convertedMessage = _converter.convert(sourceMessage, mock(NamedAddressSpace.class));
@@ -99,11 +98,11 @@
     }
 
     @Test
-    public void testAmqpValueWithNullWithMessageAnnotation()
+    void amqpValueWithNullWithMessageAnnotation()
     {
         final Object expected = null;
         final AmqpValue amqpValue = new AmqpValue(expected);
-        Message_1_0 sourceMessage =
+        final Message_1_0 sourceMessage =
                 createTestMessage(MESSAGE_MESSAGE_ANNOTATION, amqpValue.createEncodingRetainingSection());
 
         final InternalMessage convertedMessage = _converter.convert(sourceMessage, mock(NamedAddressSpace.class));
@@ -113,11 +112,12 @@
     }
 
     @Test
-    public void testAmqpValueWithNullWithObjectMessageAnnotation()
+    void amqpValueWithNullWithObjectMessageAnnotation()
     {
         final Object expected = null;
         final AmqpValue amqpValue = new AmqpValue(expected);
-        Message_1_0 sourceMessage = createTestMessage(OBJECT_MESSAGE_MESSAGE_ANNOTATION, amqpValue.createEncodingRetainingSection());
+        final Message_1_0 sourceMessage =
+                createTestMessage(OBJECT_MESSAGE_MESSAGE_ANNOTATION, amqpValue.createEncodingRetainingSection());
 
         final InternalMessage convertedMessage = _converter.convert(sourceMessage, mock(NamedAddressSpace.class));
 
@@ -127,11 +127,12 @@
     }
 
     @Test
-    public void testAmqpValueWithNullWithMapMessageAnnotation()
+    void amqpValueWithNullWithMapMessageAnnotation()
     {
         final Object expected = null;
         final AmqpValue amqpValue = new AmqpValue(expected);
-        Message_1_0 sourceMessage = createTestMessage(MAP_MESSAGE_MESSAGE_ANNOTATION, amqpValue.createEncodingRetainingSection());
+        final Message_1_0 sourceMessage =
+                createTestMessage(MAP_MESSAGE_MESSAGE_ANNOTATION, amqpValue.createEncodingRetainingSection());
 
         final InternalMessage convertedMessage = _converter.convert(sourceMessage, mock(NamedAddressSpace.class));
 
@@ -140,11 +141,12 @@
     }
 
     @Test
-    public void testAmqpValueWithNullWithBytesMessageAnnotation()
+    void amqpValueWithNullWithBytesMessageAnnotation()
     {
         final Object expected = null;
         final AmqpValue amqpValue = new AmqpValue(expected);
-        Message_1_0 sourceMessage = createTestMessage(BYTE_MESSAGE_MESSAGE_ANNOTATION, amqpValue.createEncodingRetainingSection());
+        final Message_1_0 sourceMessage =
+                createTestMessage(BYTE_MESSAGE_MESSAGE_ANNOTATION, amqpValue.createEncodingRetainingSection());
 
         final InternalMessage convertedMessage = _converter.convert(sourceMessage, mock(NamedAddressSpace.class));
 
@@ -154,11 +156,12 @@
     }
 
     @Test
-    public void testAmqpValueWithNullWithStreamMessageAnnotation()
+    void amqpValueWithNullWithStreamMessageAnnotation()
     {
         final Object expected = null;
         final AmqpValue amqpValue = new AmqpValue(expected);
-        Message_1_0 sourceMessage = createTestMessage(STREAM_MESSAGE_MESSAGE_ANNOTATION, amqpValue.createEncodingRetainingSection());
+        final Message_1_0 sourceMessage =
+                createTestMessage(STREAM_MESSAGE_MESSAGE_ANNOTATION, amqpValue.createEncodingRetainingSection());
 
         final InternalMessage convertedMessage = _converter.convert(sourceMessage, mock(NamedAddressSpace.class));
 
@@ -167,14 +170,13 @@
     }
 
     @Test
-    public void testAmqpValueWithNullWithUnknownMessageAnnotation()
+    void amqpValueWithNullWithUnknownMessageAnnotation()
     {
         final Object expected = null;
         final AmqpValue amqpValue = new AmqpValue(expected);
-        Message_1_0 sourceMessage =
-                createTestMessage(new MessageAnnotations(Collections.singletonMap(Symbol.valueOf("x-opt-jms-msg-type"),
-                                                                                  (byte) 11)),
-                                  amqpValue.createEncodingRetainingSection());
+        final Message_1_0 sourceMessage =
+                createTestMessage(new MessageAnnotations(Map.of(Symbol.valueOf("x-opt-jms-msg-type"), (byte) 11)),
+                        amqpValue.createEncodingRetainingSection());
 
         final InternalMessage convertedMessage = _converter.convert(sourceMessage, mock(NamedAddressSpace.class));
 
@@ -183,14 +185,14 @@
     }
 
     @Test
-    public void testAmqpValueWithNullWithContentType()
+    void amqpValueWithNullWithContentType()
     {
-        Properties properties = new Properties();
+        final Properties properties = new Properties();
         final String mimeType = "foo/bar";
         properties.setContentType(Symbol.valueOf(mimeType));
         final Object expected = null;
         final AmqpValue amqpValue = new AmqpValue(expected);
-        Message_1_0 sourceMessage = createTestMessage(properties, amqpValue.createEncodingRetainingSection());
+        final Message_1_0 sourceMessage = createTestMessage(properties, amqpValue.createEncodingRetainingSection());
 
         final InternalMessage convertedMessage = _converter.convert(sourceMessage, mock(NamedAddressSpace.class));
 
@@ -199,11 +201,11 @@
     }
 
     @Test
-    public void testAmqpValueWithNull()
+    void amqpValueWithNull()
     {
         final Object expected = null;
         final AmqpValue amqpValue = new AmqpValue(expected);
-        Message_1_0 sourceMessage = createTestMessage(amqpValue.createEncodingRetainingSection());
+        final Message_1_0 sourceMessage = createTestMessage(amqpValue.createEncodingRetainingSection());
 
         final InternalMessage convertedMessage = _converter.convert(sourceMessage, mock(NamedAddressSpace.class));
 
@@ -212,11 +214,11 @@
     }
 
     @Test
-    public void testAmqpValueWithString()
+    void amqpValueWithString()
     {
         final String expected = "testContent";
         final AmqpValue amqpValue = new AmqpValue(expected);
-        Message_1_0 sourceMessage = createTestMessage(amqpValue.createEncodingRetainingSection());
+        final Message_1_0 sourceMessage = createTestMessage(amqpValue.createEncodingRetainingSection());
 
         final InternalMessage convertedMessage = _converter.convert(sourceMessage, mock(NamedAddressSpace.class));
 
@@ -226,14 +228,14 @@
     }
 
     @Test
-    public void testAmqpValueWithStringWithKnownTextualContentType()
+    void amqpValueWithStringWithKnownTextualContentType()
     {
-        Properties properties = new Properties();
+        final Properties properties = new Properties();
         final String mimeType = "text/foo";
         properties.setContentType(Symbol.valueOf(mimeType));
         final Object expected = "content";
         final AmqpValue amqpValue = new AmqpValue(expected);
-        Message_1_0 sourceMessage = createTestMessage(properties, amqpValue.createEncodingRetainingSection());
+        final Message_1_0 sourceMessage = createTestMessage(properties, amqpValue.createEncodingRetainingSection());
 
         final InternalMessage convertedMessage = _converter.convert(sourceMessage, mock(NamedAddressSpace.class));
 
@@ -242,14 +244,14 @@
     }
 
     @Test
-    public void testAmqpValueWithStringWithUnknownTextualContentType()
+    void amqpValueWithStringWithUnknownTextualContentType()
     {
-        Properties properties = new Properties();
+        final Properties properties = new Properties();
         final String mimeType = "foo/bar";
         properties.setContentType(Symbol.valueOf(mimeType));
         final Object expected = "content";
         final AmqpValue amqpValue = new AmqpValue(expected);
-        Message_1_0 sourceMessage = createTestMessage(properties, amqpValue.createEncodingRetainingSection());
+        final Message_1_0 sourceMessage = createTestMessage(properties, amqpValue.createEncodingRetainingSection());
 
         final InternalMessage convertedMessage = _converter.convert(sourceMessage, mock(NamedAddressSpace.class));
 
@@ -259,7 +261,7 @@
 
 
     @Test
-    public void testAmqpValueWithMap()
+    void amqpValueWithMap()
     {
         final Map<Object, Object> originalMap = new LinkedHashMap<>();
         originalMap.put("binaryEntry", new Binary(new byte[]{0x00, (byte) 0xFF}));
@@ -267,15 +269,15 @@
         originalMap.put("uuidEntry", UUID.randomUUID());
         originalMap.put("nullEntry", null);
         originalMap.put(43, "nonstringkey");
-        originalMap.put("mapEntry", Collections.singletonMap("foo", "bar"));
+        originalMap.put("mapEntry", Map.of("foo", "bar"));
         final AmqpValue amqpValue = new AmqpValue(originalMap);
-        Message_1_0 sourceMessage = createTestMessage(amqpValue.createEncodingRetainingSection());
+        final Message_1_0 sourceMessage = createTestMessage(amqpValue.createEncodingRetainingSection());
 
         final InternalMessage convertedMessage = _converter.convert(sourceMessage, mock(NamedAddressSpace.class));
 
         assertNull(convertedMessage.getMessageHeader().getMimeType(), "Unexpected mime type");
 
-        Map<Object, Object> convertedMap = (Map<Object, Object>) convertedMessage.getMessageBody();
+        final Map<Object, Object> convertedMap = (Map<Object, Object>) convertedMessage.getMessageBody();
 
         assertEquals(originalMap.size(), (long) convertedMap.size(), "Unexpected size");
         assertArrayEquals(((Binary) originalMap.get("binaryEntry")).getArray(), (byte[]) convertedMap.get("binaryEntry"),
@@ -289,21 +291,21 @@
     }
 
     @Test
-    public void testAmqpValueWithList()
+    void amqpValueWithList()
     {
         final List<Object> originalList = new ArrayList<>();
         originalList.add(new Binary(new byte[]{0x00, (byte) 0xFF}));
         originalList.add(42);
         originalList.add(null);
-        originalList.add(Collections.singletonMap("foo", "bar"));
+        originalList.add(Map.of("foo", "bar"));
         final AmqpValue amqpValue = new AmqpValue(originalList);
-        Message_1_0 sourceMessage = createTestMessage(amqpValue.createEncodingRetainingSection());
+        final Message_1_0 sourceMessage = createTestMessage(amqpValue.createEncodingRetainingSection());
 
         final InternalMessage convertedMessage = _converter.convert(sourceMessage, mock(NamedAddressSpace.class));
 
         assertNull(convertedMessage.getMessageHeader().getMimeType(), "Unexpected mime type");
 
-        List<Object> convertedList = ((List<Object>) convertedMessage.getMessageBody());
+        final List<Object> convertedList = ((List<Object>) convertedMessage.getMessageBody());
         assertEquals(originalList.size(), (long) convertedList.size(), "Unexpected size");
         assertArrayEquals(((Binary) originalList.get(0)).getArray(), (byte[]) convertedList.get(0),
                 "Unexpected binary item");
@@ -313,16 +315,15 @@
                 "Unexpected map item");
     }
 
-
     @Test
-    public void testAmqpValueWithAmqpType()
+    void amqpValueWithAmqpType()
     {
         final Date originalValue = new Date();
         final AmqpValue amqpValue = new AmqpValue(originalValue);
-        Properties properties = new Properties();
+        final Properties properties = new Properties();
         final String mimeType = "foo/bar";
         properties.setContentType(Symbol.valueOf(mimeType));
-        Message_1_0 sourceMessage = createTestMessage(properties, amqpValue.createEncodingRetainingSection());
+        final Message_1_0 sourceMessage = createTestMessage(properties, amqpValue.createEncodingRetainingSection());
 
         final InternalMessage convertedMessage = _converter.convert(sourceMessage, mock(NamedAddressSpace.class));
 
@@ -331,33 +332,32 @@
     }
 
     @Test
-    public void testAmqpSequenceWithSimpleTypes()
+    void amqpSequenceWithSimpleTypes()
     {
         final List<Object> originalList = new ArrayList<>();
         originalList.add(37);
         originalList.add(42F);
         final AmqpSequence amqpSequence = new AmqpSequence(originalList);
-        Message_1_0 sourceMessage = createTestMessage(amqpSequence.createEncodingRetainingSection());
+        final Message_1_0 sourceMessage = createTestMessage(amqpSequence.createEncodingRetainingSection());
 
         final InternalMessage convertedMessage = _converter.convert(sourceMessage, mock(NamedAddressSpace.class));
 
         assertNull(convertedMessage.getMessageHeader().getMimeType(), "Unexpected mime type");
-        List<Object> convertedList = ((List<Object>) convertedMessage.getMessageBody());
+        final List<Object> convertedList = ((List<Object>) convertedMessage.getMessageBody());
         assertEquals(originalList.size(), (long) convertedList.size(), "Unexpected size");
         assertEquals(originalList.get(0), convertedList.get(0), "Unexpected first item");
         assertEquals(originalList.get(1), convertedList.get(1), "Unexpected second item");
     }
 
     @Test
-    public void testDataWithMessageAnnotation()
+    void dataWithMessageAnnotation()
     {
         final byte[] data = "helloworld".getBytes(UTF_8);
         doTestDataWithAnnotation(data, MESSAGE_MESSAGE_ANNOTATION, null, "application/octet-stream");
-
     }
 
     @Test
-    public void testDataWithMessageAnnotationWithContentType()
+    void dataWithMessageAnnotationWithContentType()
     {
         final byte[] data = "helloworld".getBytes(UTF_8);
         final String mimeType = "foo/bar";
@@ -365,106 +365,94 @@
     }
 
     @Test
-    public void testDataWithObjectMessageAnnotation() throws Exception
+    void dataWithObjectMessageAnnotation() throws Exception
     {
-        byte[] bytes = "helloworld".getBytes(UTF_8);
+        final byte[] bytes = "helloworld".getBytes(UTF_8);
         final byte[] expected = getObjectBytes(bytes);
-        doTestDataWithAnnotation(expected, OBJECT_MESSAGE_MESSAGE_ANNOTATION,
-                                 null,
-                                 "application/x-java-serialized-object");
+        doTestDataWithAnnotation(expected, OBJECT_MESSAGE_MESSAGE_ANNOTATION, null, "application/x-java-serialized-object");
     }
 
     @Test
-    public void testDataWithObjectMessageAnnotationWithContentType() throws Exception
+    void dataWithObjectMessageAnnotationWithContentType() throws Exception
     {
-        byte[] bytes = "helloworld".getBytes(UTF_8);
+        final byte[] bytes = "helloworld".getBytes(UTF_8);
         final byte[] expected = getObjectBytes(bytes);
         final String mimeType = "foo/bar";
         doTestDataWithAnnotation(expected, OBJECT_MESSAGE_MESSAGE_ANNOTATION, mimeType, mimeType);
     }
 
     @Test
-    public void testDataWithMapMessageAnnotation()
+    void dataWithMapMessageAnnotation()
     {
-        doTestDataWithAnnotation("helloworld".getBytes(UTF_8),
-                                 MAP_MESSAGE_MESSAGE_ANNOTATION,
-                                 null, "application/octet-stream");
+        doTestDataWithAnnotation("helloworld".getBytes(UTF_8), MAP_MESSAGE_MESSAGE_ANNOTATION, null,
+                "application/octet-stream");
     }
 
     @Test
-    public void testDataWithMapMessageAnnotationWithContentType()
+    void dataWithMapMessageAnnotationWithContentType()
     {
         final String mimeType = "foor/bar";
-        doTestDataWithAnnotation("helloworld".getBytes(UTF_8),
-                                 MAP_MESSAGE_MESSAGE_ANNOTATION,
-                                 mimeType, mimeType);
+        doTestDataWithAnnotation("helloworld".getBytes(UTF_8), MAP_MESSAGE_MESSAGE_ANNOTATION, mimeType, mimeType);
     }
 
     @Test
-    public void testDataWithBytesMessageAnnotation()
+    void dataWithBytesMessageAnnotation()
     {
-        doTestDataWithAnnotation("helloworld".getBytes(UTF_8),
-                                 BYTE_MESSAGE_MESSAGE_ANNOTATION,
-                                 null, "application/octet-stream");
+        doTestDataWithAnnotation("helloworld".getBytes(UTF_8), BYTE_MESSAGE_MESSAGE_ANNOTATION, null,
+                "application/octet-stream");
     }
 
     @Test
-    public void testDataWithBytesMessageAnnotationWithContentType()
+    void dataWithBytesMessageAnnotationWithContentType()
     {
         final String mimeType = "foo/bar";
-        doTestDataWithAnnotation("helloworld".getBytes(UTF_8),
-                                 BYTE_MESSAGE_MESSAGE_ANNOTATION,
-                                 mimeType, mimeType);
+        doTestDataWithAnnotation("helloworld".getBytes(UTF_8), BYTE_MESSAGE_MESSAGE_ANNOTATION, mimeType, mimeType);
     }
 
     @Test
-    public void testDataWithStreamMessageAnnotation()
+    void dataWithStreamMessageAnnotation()
     {
-        doTestDataWithAnnotation("helloworld".getBytes(UTF_8), STREAM_MESSAGE_MESSAGE_ANNOTATION,
-                                 null, "application/octet-stream");
+        doTestDataWithAnnotation("helloworld".getBytes(UTF_8), STREAM_MESSAGE_MESSAGE_ANNOTATION, null,
+                "application/octet-stream");
     }
 
     @Test
-    public void testDataWithStreamMessageAnnotationWithContentType()
+    void dataWithStreamMessageAnnotationWithContentType()
     {
         final String mimeType = "foo/bar";
-        doTestDataWithAnnotation("helloworld".getBytes(UTF_8), STREAM_MESSAGE_MESSAGE_ANNOTATION,
-                                 mimeType, mimeType);
+        doTestDataWithAnnotation("helloworld".getBytes(UTF_8), STREAM_MESSAGE_MESSAGE_ANNOTATION, mimeType, mimeType);
     }
 
     @Test
-    public void testDataWithTextMessageAnnotation()
+    void dataWithTextMessageAnnotation()
     {
-        doTestDataWithAnnotation("helloworld".getBytes(UTF_8), TEXT_MESSAGE_MESSAGE_ANNOTATION, null, "application/octet-stream");
+        doTestDataWithAnnotation("helloworld".getBytes(UTF_8), TEXT_MESSAGE_MESSAGE_ANNOTATION, null,
+                "application/octet-stream");
     }
 
     @Test
-    public void testDataWithTextMessageAnnotationWithContentType()
+    void dataWithTextMessageAnnotationWithContentType()
     {
         doTestDataWithAnnotation("helloworld".getBytes(UTF_8), TEXT_MESSAGE_MESSAGE_ANNOTATION, "foo/bar", "foo/bar");
     }
 
     @Test
-    public void testDataWithUnsupportedMessageAnnotation()
+    void dataWithUnsupportedMessageAnnotation()
     {
         doTestDataWithAnnotation("helloworld".getBytes(UTF_8),
-                                 new MessageAnnotations(Collections.singletonMap(Symbol.valueOf("x-opt-jms-msg-type"),
-                                                                                 (byte) 11)),
-                                 null, "application/octet-stream");
+                new MessageAnnotations(Map.of(Symbol.valueOf("x-opt-jms-msg-type"), (byte) 11)), null, "application/octet-stream");
     }
 
     @Test
-    public void testDataWithUnsupportedMessageAnnotationWithContentType()
+    void dataWithUnsupportedMessageAnnotationWithContentType()
     {
         final String mimeType = "foo/bar";
         doTestDataWithAnnotation("helloworld".getBytes(UTF_8),
-                                 new MessageAnnotations(Collections.singletonMap(Symbol.valueOf("x-opt-jms-msg-type"),
-                                                                                 (byte) 11)),
-                                 mimeType, mimeType);
+                new MessageAnnotations(Map.of(Symbol.valueOf("x-opt-jms-msg-type"), (byte) 11)), mimeType, mimeType);
     }
 
     @Test
-    public void testData() throws Exception
+    void data() throws Exception
     {
         final byte[] expected = getObjectBytes("helloworld".getBytes(UTF_8));
         final Data value = new Data(new Binary(expected));
@@ -478,10 +466,9 @@
     }
 
     @Test
-    public void testNoBodyWithMessageAnnotation()
+    void noBodyWithMessageAnnotation()
     {
-        Message_1_0 sourceMessage = createTestMessage(MESSAGE_MESSAGE_ANNOTATION, null);
-
+        final Message_1_0 sourceMessage = createTestMessage(MESSAGE_MESSAGE_ANNOTATION, null);
         final InternalMessage convertedMessage = _converter.convert(sourceMessage, mock(NamedAddressSpace.class));
 
         assertNull(convertedMessage.getMessageHeader().getMimeType(), "Unexpected mime type");
@@ -489,10 +476,9 @@
     }
 
     @Test
-    public void testNoBodyWithObjectMessageAnnotation()
+    void noBodyWithObjectMessageAnnotation()
     {
-        Message_1_0 sourceMessage = createTestMessage(OBJECT_MESSAGE_MESSAGE_ANNOTATION, null);
-
+        final Message_1_0 sourceMessage = createTestMessage(OBJECT_MESSAGE_MESSAGE_ANNOTATION, null);
         final InternalMessage convertedMessage = _converter.convert(sourceMessage, mock(NamedAddressSpace.class));
 
         assertEquals("application/x-java-serialized-object", convertedMessage.getMessageHeader().getMimeType(),
@@ -502,10 +488,9 @@
     }
 
     @Test
-    public void testNoBodyWithMapMessageAnnotation()
+    void noBodyWithMapMessageAnnotation()
     {
-        Message_1_0 sourceMessage = createTestMessage(MAP_MESSAGE_MESSAGE_ANNOTATION, null);
-
+        final Message_1_0 sourceMessage = createTestMessage(MAP_MESSAGE_MESSAGE_ANNOTATION, null);
         final InternalMessage convertedMessage = _converter.convert(sourceMessage, mock(NamedAddressSpace.class));
 
         assertNull(convertedMessage.getMessageHeader().getMimeType(), "Unexpected mime type");
@@ -513,10 +498,9 @@
     }
 
     @Test
-    public void testNoBodyWithBytesMessageAnnotation()
+    void noBodyWithBytesMessageAnnotation()
     {
-        Message_1_0 sourceMessage = createTestMessage(BYTE_MESSAGE_MESSAGE_ANNOTATION, null);
-
+        final Message_1_0 sourceMessage = createTestMessage(BYTE_MESSAGE_MESSAGE_ANNOTATION, null);
         final InternalMessage convertedMessage = _converter.convert(sourceMessage, mock(NamedAddressSpace.class));
 
         assertEquals("application/octet-stream", convertedMessage.getMessageHeader().getMimeType(),
@@ -525,10 +509,9 @@
     }
 
     @Test
-    public void testNoBodyWithStreamMessageAnnotation()
+    void noBodyWithStreamMessageAnnotation()
     {
-        Message_1_0 sourceMessage = createTestMessage(STREAM_MESSAGE_MESSAGE_ANNOTATION, null);
-
+        final Message_1_0 sourceMessage = createTestMessage(STREAM_MESSAGE_MESSAGE_ANNOTATION, null);
         final InternalMessage convertedMessage = _converter.convert(sourceMessage, mock(NamedAddressSpace.class));
 
         assertNull(convertedMessage.getMessageHeader().getMimeType(), "Unexpected mime type");
@@ -536,10 +519,9 @@
     }
 
     @Test
-    public void testNoBodyWithTextMessageAnnotation()
+    void noBodyWithTextMessageAnnotation()
     {
-        Message_1_0 sourceMessage = createTestMessage(TEXT_MESSAGE_MESSAGE_ANNOTATION, null);
-
+        final Message_1_0 sourceMessage = createTestMessage(TEXT_MESSAGE_MESSAGE_ANNOTATION, null);
         final InternalMessage convertedMessage = _converter.convert(sourceMessage, mock(NamedAddressSpace.class));
 
         assertEquals("text/plain", convertedMessage.getMessageHeader().getMimeType(),
@@ -548,13 +530,13 @@
     }
 
     @Test
-    public void testNoBodyWithTextMessageAnnotationWithKnownTextualContentType()
+    void noBodyWithTextMessageAnnotationWithKnownTextualContentType()
     {
         final String mimeType = "text/foo";
-        Properties properties = new Properties();
+        final Properties properties = new Properties();
         properties.setContentType(Symbol.valueOf(mimeType));
 
-        Message_1_0 sourceMessage = createTestMessage(properties, TEXT_MESSAGE_MESSAGE_ANNOTATION, null);
+        final Message_1_0 sourceMessage = createTestMessage(properties, TEXT_MESSAGE_MESSAGE_ANNOTATION, null);
 
         final InternalMessage convertedMessage = _converter.convert(sourceMessage, mock(NamedAddressSpace.class));
 
@@ -563,12 +545,12 @@
     }
 
     @Test
-    public void testNoBodyWithTextMessageAnnotationWithUnknownTextualContentType()
+    void noBodyWithTextMessageAnnotationWithUnknownTextualContentType()
     {
         final String mimeType = "foo/bar";
-        Properties properties = new Properties();
+        final Properties properties = new Properties();
         properties.setContentType(Symbol.valueOf(mimeType));
-        Message_1_0 sourceMessage = createTestMessage(properties, TEXT_MESSAGE_MESSAGE_ANNOTATION, null);
+        final Message_1_0 sourceMessage = createTestMessage(properties, TEXT_MESSAGE_MESSAGE_ANNOTATION, null);
 
         final InternalMessage convertedMessage = _converter.convert(sourceMessage, mock(NamedAddressSpace.class));
 
@@ -579,11 +561,10 @@
 
 
     @Test
-    public void testNoBodyWithUnknownMessageAnnotation()
+    void noBodyWithUnknownMessageAnnotation()
     {
-        Message_1_0 sourceMessage =
-                createTestMessage(new MessageAnnotations(Collections.singletonMap(Symbol.valueOf("x-opt-jms-msg-type"),
-                                                                                  (byte) 11)), null);
+        final Message_1_0 sourceMessage =
+                createTestMessage(new MessageAnnotations(Map.of(Symbol.valueOf("x-opt-jms-msg-type"), (byte) 11)), null);
 
         final InternalMessage convertedMessage = _converter.convert(sourceMessage, mock(NamedAddressSpace.class));
 
@@ -592,14 +573,13 @@
     }
 
     @Test
-    public void testNoBodyWithUnknownMessageAnnotationWithContentType()
+    void noBodyWithUnknownMessageAnnotationWithContentType()
     {
-
         final String mimeType = "foo/bar";
-        Properties properties = new Properties();
+        final Properties properties = new Properties();
         properties.setContentType(Symbol.valueOf(mimeType));
-        Message_1_0 sourceMessage =
-                createTestMessage(properties, new MessageAnnotations(Collections.singletonMap(Symbol.valueOf("x-opt-jms-msg-type"),
+        final Message_1_0 sourceMessage =
+                createTestMessage(properties, new MessageAnnotations(Map.of(Symbol.valueOf("x-opt-jms-msg-type"),
                                                                                   (byte) 11)), null);
 
         final InternalMessage convertedMessage = _converter.convert(sourceMessage, mock(NamedAddressSpace.class));
@@ -609,7 +589,7 @@
     }
 
     @Test
-    public void testNoBody()
+    void noBody()
     {
         final Message_1_0 sourceMessage = createTestMessage(null);
 
@@ -620,10 +600,10 @@
     }
 
     @Test
-    public void testNoBodyWithContentTypeApplicationOctetStream()
+    void noBodyWithContentTypeApplicationOctetStream()
     {
         final String mimeType = "foo/bar";
-        Properties properties = new Properties();
+        final Properties properties = new Properties();
         properties.setContentType(Symbol.valueOf(mimeType));
         final Message_1_0 sourceMessage = createTestMessage(properties, null);
 
@@ -634,7 +614,7 @@
     }
 
     @Test
-    public void testMessageAnnotationTakesPrecedenceOverContentType()
+    void messageAnnotationTakesPrecedenceOverContentType()
     {
         final Properties properties = new Properties();
         properties.setContentType(Symbol.valueOf("application/octet-stream"));
@@ -647,43 +627,43 @@
         assertNull(convertedMessage.getMessageBody(), "Unexpected content");
     }
 
-    private Message_1_0 createTestMessage(final EncodingRetainingSection encodingRetainingSection)
+    private Message_1_0 createTestMessage(final EncodingRetainingSection<?> encodingRetainingSection)
     {
         return createTestMessage(new Properties(), encodingRetainingSection);
     }
 
-    private Message_1_0 createTestMessage(final Properties properties, final EncodingRetainingSection section)
+    private Message_1_0 createTestMessage(final Properties properties, final EncodingRetainingSection<?> section)
     {
         return createTestMessage(new Header(),
-                                 new DeliveryAnnotations(Collections.emptyMap()),
-                                 new MessageAnnotations(Collections.emptyMap()),
+                                 new DeliveryAnnotations(Map.of()),
+                                 new MessageAnnotations(Map.of()),
                                  properties,
-                                 new ApplicationProperties(Collections.emptyMap()),
+                                 new ApplicationProperties(Map.of()),
                                  0,
                                  section);
     }
 
     private Message_1_0 createTestMessage(final Properties properties,
                                           final MessageAnnotations messageAnnotations,
-                                          final EncodingRetainingSection section)
+                                          final EncodingRetainingSection<?> section)
     {
         return createTestMessage(new Header(),
-                                 new DeliveryAnnotations(Collections.emptyMap()),
+                                 new DeliveryAnnotations(Map.of()),
                                  messageAnnotations,
                                  properties,
-                                 new ApplicationProperties(Collections.emptyMap()),
+                                 new ApplicationProperties(Map.of()),
                                  0,
                                  section);
     }
 
     private Message_1_0 createTestMessage(final MessageAnnotations messageAnnotations,
-                                          final EncodingRetainingSection section)
+                                          final EncodingRetainingSection<?> section)
     {
         return createTestMessage(new Header(),
-                                 new DeliveryAnnotations(Collections.emptyMap()),
+                                 new DeliveryAnnotations(Map.of()),
                                  messageAnnotations,
                                  new Properties(),
-                                 new ApplicationProperties(Collections.emptyMap()),
+                                 new ApplicationProperties(Map.of()),
                                  0,
                                  section);
     }
@@ -694,17 +674,17 @@
                                           final Properties properties,
                                           final ApplicationProperties applicationProperties,
                                           final long arrivalTime,
-                                          final EncodingRetainingSection section)
+                                          final EncodingRetainingSection<?> section)
     {
         final StoredMessage<MessageMetaData_1_0> storedMessage = mock(StoredMessage.class);
-        MessageMetaData_1_0 metaData = new MessageMetaData_1_0(header.createEncodingRetainingSection(),
-                                                               deliveryAnnotations.createEncodingRetainingSection(),
-                                                               messageAnnotations.createEncodingRetainingSection(),
-                                                               properties.createEncodingRetainingSection(),
-                                                               applicationProperties.createEncodingRetainingSection(),
-                                                               new Footer(Collections.emptyMap()).createEncodingRetainingSection(),
-                                                               arrivalTime,
-                                                               0);
+        final MessageMetaData_1_0 metaData = new MessageMetaData_1_0(header.createEncodingRetainingSection(),
+                deliveryAnnotations.createEncodingRetainingSection(),
+                messageAnnotations.createEncodingRetainingSection(),
+                properties.createEncodingRetainingSection(),
+                applicationProperties.createEncodingRetainingSection(),
+                new Footer(Map.of()).createEncodingRetainingSection(),
+                arrivalTime,
+                0);
         when(storedMessage.getMetaData()).thenReturn(metaData);
 
         if (section != null)
@@ -715,9 +695,8 @@
             final ArgumentCaptor<Integer> offsetCaptor = ArgumentCaptor.forClass(Integer.class);
             final ArgumentCaptor<Integer> sizeCaptor = ArgumentCaptor.forClass(Integer.class);
 
-            when(storedMessage.getContent(offsetCaptor.capture(),
-                                          sizeCaptor.capture())).then(invocation -> combined.view(offsetCaptor.getValue(),
-                                                                                                  sizeCaptor.getValue()));
+            when(storedMessage.getContent(offsetCaptor.capture(), sizeCaptor.capture()))
+                    .then(invocation -> combined.view(offsetCaptor.getValue(), sizeCaptor.getValue()));
         }
         else
         {
@@ -729,8 +708,8 @@
     private byte[] getObjectBytes(final Object object) throws IOException
     {
         final byte[] expected;
-        try (ByteArrayOutputStream baos = new ByteArrayOutputStream();
-             ObjectOutputStream oos = new ObjectOutputStream(baos))
+        try (final ByteArrayOutputStream baos = new ByteArrayOutputStream();
+             final ObjectOutputStream oos = new ObjectOutputStream(baos))
         {
             oos.writeObject(object);
             expected = baos.toByteArray();
@@ -745,10 +724,10 @@
 
         final Data value = new Data(new Binary(data));
 
-        Message_1_0 sourceMessage;
+        final Message_1_0 sourceMessage;
         if (mimeType != null)
         {
-            Properties properties = new Properties();
+            final Properties properties = new Properties();
             properties.setContentType(Symbol.valueOf(mimeType));
             sourceMessage = createTestMessage(properties, messageAnnotations, value.createEncodingRetainingSection());
         }
@@ -762,7 +741,5 @@
         assertEquals(expectedMimeType, convertedMessage.getMessageHeader().getMimeType(),
                 "Unexpected mime type");
         assertArrayEquals(data, ((byte[]) convertedMessage.getMessageBody()), "Unexpected content");
-
     }
-
 }
\ No newline at end of file
diff --git a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/Message_1_0_MutatorTest.java b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/Message_1_0_MutatorTest.java
index 59f9a34..d8793f3 100644
--- a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/Message_1_0_MutatorTest.java
+++ b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/Message_1_0_MutatorTest.java
@@ -24,8 +24,8 @@
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.MatcherAssert.assertThat;
 
-import java.util.Collections;
 import java.util.List;
+import java.util.Map;
 
 import org.junit.jupiter.api.AfterAll;
 import org.junit.jupiter.api.BeforeAll;
@@ -49,50 +49,51 @@
 import org.apache.qpid.server.store.TestMemoryMessageStore;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class Message_1_0_MutatorTest extends UnitTestBase
+class Message_1_0_MutatorTest extends UnitTestBase
 {
     private static final byte TEST_PRIORITY = (byte) 1;
     private static final String TEST_HEADER_NAME = "foo";
     private static final String TEST_HEADER_VALUE = "bar";
     private static final String TEST_CONTENT_TYPE = "text/plain";
     private static final String TEST_CONTENT = "testContent";
+
     private MessageStore _messageStore;
     private Message_1_0_Mutator _messageMutator;
 
     @BeforeAll
-    public void beforeAll()
+    void beforeAll()
     {
         _messageStore = new TestMemoryMessageStore();
     }
 
     @BeforeEach
-    public void beforeEach()
+    void beforeEach()
     {
         final Message_1_0 message = createTestMessage();
         _messageMutator = new Message_1_0_Mutator(message, _messageStore);
     }
 
     @AfterAll
-    public void tearDown()
+    void tearDown()
     {
         _messageStore.closeMessageStore();
     }
 
     @Test
-    public void setPriority()
+    void setPriority()
     {
         _messageMutator.setPriority((byte) (TEST_PRIORITY + 1));
         assertThat(_messageMutator.getPriority(), is(equalTo((byte) (TEST_PRIORITY + 1))));
     }
 
     @Test
-    public void getPriority()
+    void getPriority()
     {
         assertThat((int) _messageMutator.getPriority(), is(equalTo((int) TEST_PRIORITY)));
     }
 
     @Test
-    public void create() throws Exception
+    void create() throws Exception
     {
         _messageMutator.setPriority((byte) (TEST_PRIORITY + 1));
 
@@ -127,17 +128,16 @@
         final PropertiesSection propertiesSection = properties.createEncodingRetainingSection();
 
         final ApplicationPropertiesSection applicationPropertiesSection =
-                new ApplicationProperties(Collections.singletonMap(TEST_HEADER_NAME, TEST_HEADER_VALUE))
-                        .createEncodingRetainingSection();
+                new ApplicationProperties(Map.of(TEST_HEADER_NAME, TEST_HEADER_VALUE)).createEncodingRetainingSection();
 
         final MessageMetaData_1_0 mmd = new MessageMetaData_1_0(headerSection,
-                                                                null,
-                                                                null,
-                                                                propertiesSection,
-                                                                applicationPropertiesSection,
-                                                                null,
-                                                                System.currentTimeMillis(),
-                                                                contentSize);
+                null,
+                null,
+                propertiesSection,
+                applicationPropertiesSection,
+                null,
+                System.currentTimeMillis(),
+                contentSize);
 
         final MessageHandle<MessageMetaData_1_0> handle = _messageStore.addMessage(mmd);
         handle.addContent(content);
diff --git a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/PropertyConverter_Internal_to_v1_0Test.java b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/PropertyConverter_Internal_to_v1_0Test.java
index cc29928..01cd1e2 100644
--- a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/PropertyConverter_Internal_to_v1_0Test.java
+++ b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/PropertyConverter_Internal_to_v1_0Test.java
@@ -26,16 +26,16 @@
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
-import static org.junit.jupiter.api.Assertions.fail;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
-import java.util.Collections;
 import java.util.Date;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.UUID;
 
@@ -55,25 +55,25 @@
 import org.apache.qpid.server.store.StoredMessage;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class PropertyConverter_Internal_to_v1_0Test extends UnitTestBase
+class PropertyConverter_Internal_to_v1_0Test extends UnitTestBase
 {
     private MessageConverter_Internal_to_v1_0 _messageConverter;
     private NamedAddressSpace _addressSpace;
 
     @BeforeAll
-    public void setUp() throws Exception
+    void setUp()
     {
         _messageConverter = new MessageConverter_Internal_to_v1_0();
         _addressSpace = mock(NamedAddressSpace.class);
     }
 
     @Test
-    public void testDurableTrueConversion()
+    void durableTrueConversion()
     {
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
-        InternalMessage originalMessage = createTestMessage(header, null, true);
+        final InternalMessage originalMessage = createTestMessage(header, null, true);
 
-        Message_1_0 convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final Message_1_0 convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertTrue(convertedMessage.isPersistent(), "Unexpected persistence of message");
         assertTrue(convertedMessage.getStoredMessage().getMetaData().isPersistent(),
@@ -81,12 +81,12 @@
     }
 
     @Test
-    public void testDurableFalseConversion()
+    void durableFalseConversion()
     {
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
-        InternalMessage originalMessage = createTestMessage(header, null, false);
+        final InternalMessage originalMessage = createTestMessage(header, null, false);
 
-        Message_1_0 convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final Message_1_0 convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertFalse(convertedMessage.isPersistent(), "Unexpected persistence of message");
         assertFalse(convertedMessage.getStoredMessage().getMetaData().isPersistent(),
@@ -94,229 +94,222 @@
     }
 
     @Test
-    public void testPriorityConversion()
+    void priorityConversion()
     {
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
         byte priority = (byte) 7;
         when(header.getPriority()).thenReturn(priority);
-        InternalMessage originalMessage = createTestMessage(header);
+        final InternalMessage originalMessage = createTestMessage(header);
 
-        Message_1_0 convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final Message_1_0 convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(priority, (long) convertedMessage.getMessageHeader().getPriority(), "Unexpected priority");
     }
 
     @Test
-    public void testExpirationConversion() throws InterruptedException
+    void expirationConversion() throws InterruptedException
     {
-        long ttl = 10000;
-        long expiryTime = System.currentTimeMillis() + ttl;
+        final long ttl = 10000;
+        final long expiryTime = System.currentTimeMillis() + ttl;
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
         when(header.getExpiration()).thenReturn(expiryTime);
-        InternalMessage originalMessage = createTestMessage(header);
+        final InternalMessage originalMessage = createTestMessage(header);
         Thread.sleep(1L);
 
-        Message_1_0 convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final Message_1_0 convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
-        Long convertedTtl = MessageConverter_from_1_0.getTtl(convertedMessage);
+        final Long convertedTtl = MessageConverter_from_1_0.getTtl(convertedMessage);
+        assertNotNull(convertedTtl);
         assertEquals(expiryTime - originalMessage.getArrivalTime(), convertedTtl.longValue(), "Unexpected TTL");
     }
 
     @Test
-    public void testContentEncodingConversion()
+    void contentEncodingConversion()
     {
-        String contentEncoding = "my-test-encoding";
+        final String contentEncoding = "my-test-encoding";
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
         when(header.getEncoding()).thenReturn(contentEncoding);
-        InternalMessage originalMessage = createTestMessage(header);
+        final InternalMessage originalMessage = createTestMessage(header);
 
-        Message_1_0 convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final Message_1_0 convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
-        Symbol convertedContentEncoding = MessageConverter_from_1_0.getContentEncoding(convertedMessage);
+        final Symbol convertedContentEncoding = MessageConverter_from_1_0.getContentEncoding(convertedMessage);
         assertEquals(contentEncoding, convertedContentEncoding.toString(), "Unexpected content encoding");
     }
 
     @Test
-    public void testMessageIdStringConversion()
+    void messageIdStringConversion()
     {
         final String messageId = "testMessageId";
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
         when(header.getMessageId()).thenReturn(messageId);
-        InternalMessage originalMessage = createTestMessage(header);
+        final InternalMessage originalMessage = createTestMessage(header);
 
-        Message_1_0 convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final Message_1_0 convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
-        Object convertedMessageId = MessageConverter_from_1_0.getMessageId(convertedMessage);
+        final Object convertedMessageId = MessageConverter_from_1_0.getMessageId(convertedMessage);
         assertEquals(messageId, convertedMessageId, "Unexpected messageId");
     }
 
     @Test
-    public void testMessageIdUuidConversion()
+    void messageIdUuidConversion()
     {
         final UUID messageId = UUID.randomUUID();
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
         when(header.getMessageId()).thenReturn(messageId.toString());
-        InternalMessage originalMessage = createTestMessage(header);
+        final InternalMessage originalMessage = createTestMessage(header);
 
-        Message_1_0 convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final Message_1_0 convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
-        Object convertedMessageId = MessageConverter_from_1_0.getMessageId(convertedMessage);
+        final Object convertedMessageId = MessageConverter_from_1_0.getMessageId(convertedMessage);
         assertEquals(messageId, convertedMessageId, "Unexpected messageId");
     }
 
     @Test
-    public void testMessageIdUnsignedLongConversion()
+    void messageIdUnsignedLongConversion()
     {
         final UnsignedLong messageId = UnsignedLong.valueOf(-1L);
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
         when(header.getMessageId()).thenReturn(messageId.toString());
-        InternalMessage originalMessage = createTestMessage(header);
+        final InternalMessage originalMessage = createTestMessage(header);
 
-        Message_1_0 convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final Message_1_0 convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
-        Object convertedMessageId = MessageConverter_from_1_0.getMessageId(convertedMessage);
+        final Object convertedMessageId = MessageConverter_from_1_0.getMessageId(convertedMessage);
         assertEquals(messageId, convertedMessageId, "Unexpected messageId");
     }
 
     @Test
-    public void testCorrelationIdStringConversion()
+    void correlationIdStringConversion()
     {
         final String correlationId = "testCorrelationId";
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
         when(header.getCorrelationId()).thenReturn(correlationId);
-        InternalMessage originalMessage = createTestMessage(header);
+        final InternalMessage originalMessage = createTestMessage(header);
 
-        Message_1_0 convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final Message_1_0 convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
-        Object convertedCorrelationId = MessageConverter_from_1_0.getCorrelationId(convertedMessage);
+        final Object convertedCorrelationId = MessageConverter_from_1_0.getCorrelationId(convertedMessage);
         assertEquals(correlationId, convertedCorrelationId, "Unexpected messageId");
     }
 
     @Test
-    public void testCorrelationIdUuidConversion()
+    void correlationIdUuidConversion()
     {
         final UUID correlationId = UUID.randomUUID();
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
         when(header.getCorrelationId()).thenReturn(correlationId.toString());
-        InternalMessage originalMessage = createTestMessage(header);
+        final InternalMessage originalMessage = createTestMessage(header);
 
-        Message_1_0 convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final Message_1_0 convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
-        Object convertedCorrelationId = MessageConverter_from_1_0.getCorrelationId(convertedMessage);
+        final Object convertedCorrelationId = MessageConverter_from_1_0.getCorrelationId(convertedMessage);
         assertEquals(correlationId, convertedCorrelationId, "Unexpected correlationId");
     }
 
     @Test
-    public void testCorrelationIdUnsignedLongConversion()
+    void correlationIdUnsignedLongConversion()
     {
         final UnsignedLong correlationId = UnsignedLong.valueOf(-1L);
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
         when(header.getCorrelationId()).thenReturn(correlationId.toString());
-        InternalMessage originalMessage = createTestMessage(header);
+        final InternalMessage originalMessage = createTestMessage(header);
 
-        Message_1_0 convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final Message_1_0 convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
-        Object convertedCorrelationId = MessageConverter_from_1_0.getCorrelationId(convertedMessage);
+        final Object convertedCorrelationId = MessageConverter_from_1_0.getCorrelationId(convertedMessage);
         assertEquals(correlationId, convertedCorrelationId, "Unexpected correlationId");
     }
 
     @Test
-    public void testUserIdConversion()
+    void userIdConversion()
     {
         final String userId = "testUserId";
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
         when(header.getUserId()).thenReturn(userId);
-        InternalMessage originalMessage = createTestMessage(header);
+        final InternalMessage originalMessage = createTestMessage(header);
 
-        Message_1_0 convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final Message_1_0 convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
-        Binary convertedUserId = MessageConverter_from_1_0.getUserId(convertedMessage);
+        final Binary convertedUserId = MessageConverter_from_1_0.getUserId(convertedMessage);
         assertArrayEquals(userId.getBytes(UTF_8), convertedUserId.getArray(), "Unexpected userId");
     }
 
     @Test
-    public void testReplyToConversion()
+    void replyToConversion()
     {
         final String replyTo = "amq.direct/test";
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
         when(header.getReplyTo()).thenReturn(replyTo);
-        InternalMessage originalMessage = createTestMessage(header);
+        final InternalMessage originalMessage = createTestMessage(header);
 
-        Message_1_0 convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final Message_1_0 convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
-        String convertedReplyTo = MessageConverter_from_1_0.getReplyTo(convertedMessage);
+        final String convertedReplyTo = MessageConverter_from_1_0.getReplyTo(convertedMessage);
         assertEquals(replyTo, convertedReplyTo, "Unexpected replyTo");
     }
 
     @Test
-    public void testToConversion()
+    void toConversion()
     {
         final String to = "amq.direct/test";
-        InternalMessage originalMessage = createTestMessage(to);
-
-        Message_1_0 convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage originalMessage = createTestMessage(to);
+        final Message_1_0 convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(to, convertedMessage.getTo(), "Unexpected to");
     }
 
     @Test
-    public void testTimestampConversion()
+    void timestampConversion()
     {
         final long timestamp = System.currentTimeMillis();
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
         when(header.getTimestamp()).thenReturn(timestamp);
-        InternalMessage originalMessage = createTestMessage(header);
+        final InternalMessage originalMessage = createTestMessage(header);
 
-        Message_1_0 convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final Message_1_0 convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
-        Date creationTime = MessageConverter_from_1_0.getCreationTime(convertedMessage);
+        final Date creationTime = MessageConverter_from_1_0.getCreationTime(convertedMessage);
         assertNotNull(creationTime, "timestamp not converted");
         assertEquals(timestamp, creationTime.getTime(), "Unexpected timestamp");
     }
 
     @Test
-    public void testHeadersConversion()
+    void headersConversion()
     {
-        final Map<String, Object> properties = new HashMap<>();
-        properties.put("testProperty1", "testProperty1Value");
-        properties.put("intProperty", 1);
+        final Map<String, Object> properties = Map.of("testProperty1", "testProperty1Value",
+                "intProperty", 1);
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
         when(header.getHeaderNames()).thenReturn(properties.keySet());
         doAnswer(invocation ->
-                 {
-                     final String originalArgument = (String) (invocation.getArguments())[0];
-                     return properties.get(originalArgument);
-                 }).when(header).getHeader(any(String.class));
-        InternalMessage originalMessage = createTestMessage(header);
+        {
+            final String originalArgument = (String) (invocation.getArguments())[0];
+            return properties.get(originalArgument);
+        }).when(header).getHeader(any(String.class));
+        final InternalMessage originalMessage = createTestMessage(header);
 
         final Message_1_0 convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
-        Map<String, Object> convertedHeaders = convertedMessage.getApplicationPropertiesSection().getValue();
+        final Map<String, Object> convertedHeaders = convertedMessage.getApplicationPropertiesSection().getValue();
         assertEquals(properties, new HashMap<>(convertedHeaders), "Unexpected application properties");
     }
 
     @Test
-    public void testHeadersConversionWithNonSimpleTypes()
+    void headersConversionWithNonSimpleTypes()
     {
-        final Map<String, Object> properties = Collections.singletonMap("listProperty", Collections.emptyList());
+        final Map<String, Object> properties = Map.of("listProperty", List.of());
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
         when(header.getHeaderNames()).thenReturn(properties.keySet());
         doAnswer(invocation ->
-                 {
-                     final String originalArgument = (String) (invocation.getArguments())[0];
-                     return properties.get(originalArgument);
-                 }).when(header).getHeader(any(String.class));
-        InternalMessage originalMessage = createTestMessage(header);
+        {
+            final String originalArgument = (String) (invocation.getArguments())[0];
+            return properties.get(originalArgument);
+        }).when(header).getHeader(any(String.class));
+        final InternalMessage originalMessage = createTestMessage(header);
 
-        try
-        {
-            _messageConverter.convert(originalMessage, _addressSpace);
-            fail("Expected exception not thrown");
-        }
-        catch (MessageConversionException e)
-        {
-            // pass
-        }
+        assertThrows(MessageConversionException.class,
+                () -> _messageConverter.convert(originalMessage, _addressSpace),
+                "Expected exception not thrown");
     }
 
     private InternalMessage createTestMessage(String to)
@@ -333,7 +326,7 @@
     }
 
     private InternalMessage createTestMessage(final AMQMessageHeader header,
-                                              byte[] content,
+                                              final byte[] content,
                                               final boolean persistent)
     {
         final InternalMessageHeader internalMessageHeader = new InternalMessageHeader(header);
diff --git a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/PropertyConverter_v1_0_to_InternalTest.java b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/PropertyConverter_v1_0_to_InternalTest.java
index 4ea9735..e7ff1d6 100644
--- a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/PropertyConverter_v1_0_to_InternalTest.java
+++ b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/PropertyConverter_v1_0_to_InternalTest.java
@@ -28,7 +28,6 @@
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
-import java.util.Collections;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.Map;
@@ -56,26 +55,26 @@
 import org.apache.qpid.server.store.StoredMessage;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class PropertyConverter_v1_0_to_InternalTest extends UnitTestBase
+class PropertyConverter_v1_0_to_InternalTest extends UnitTestBase
 {
     private MessageConverter_v1_0_to_Internal _messageConverter;
     private NamedAddressSpace _addressSpace;
 
     @BeforeAll
-    public void setUp() throws Exception
+    void setUp()
     {
         _messageConverter = new MessageConverter_v1_0_to_Internal();
         _addressSpace = mock(NamedAddressSpace.class);
     }
 
     @Test
-    public void testDurableTrueConversion()
+    void durableTrueConversion()
     {
         final Header header = new Header();
         header.setDurable(true);
         final Message_1_0 originalMessage = createTestMessage(header);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertTrue(convertedMessage.isPersistent(), "Unexpected persistence of message");
         assertTrue(convertedMessage.getStoredMessage().getMetaData().isPersistent(),
@@ -83,13 +82,13 @@
     }
 
     @Test
-    public void testDurableFalseConversion()
+    void durableFalseConversion()
     {
         final Header header = new Header();
         header.setDurable(false);
         final Message_1_0 originalMessage = createTestMessage(header);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertFalse(convertedMessage.isPersistent(), "Unexpected persistence of message");
         assertFalse(convertedMessage.getStoredMessage().getMetaData().isPersistent(),
@@ -97,70 +96,69 @@
     }
 
     @Test
-    public void testPriorityConversion()
+    void priorityConversion()
     {
         final byte priority = 7;
         final Header header = new Header();
         header.setPriority(UnsignedByte.valueOf(priority));
         final Message_1_0 originalMessage = createTestMessage(header);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(priority, (long) convertedMessage.getMessageHeader().getPriority(), "Unexpected priority");
     }
 
     @Test
-    public void testAbsoluteExpiryTimeConversion()
+    void absoluteExpiryTimeConversion()
     {
         long ttl = 10000;
         long arrivalTime = System.currentTimeMillis();
         long expiryTime = arrivalTime + ttl;
-        Properties properties = new Properties();
+        final Properties properties = new Properties();
         properties.setAbsoluteExpiryTime(new Date(expiryTime));
-        Message_1_0 originalMessage = createTestMessage(properties, arrivalTime);
+        final Message_1_0 originalMessage = createTestMessage(properties, arrivalTime);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(0, convertedMessage.getMessageHeader().getExpiration(), "Unexpected expiration");
     }
 
     @Test
-    public void testTTLConversion()
+    void TTLConversion()
     {
-        long ttl = 10000;
-        long arrivalTime = System.currentTimeMillis();
-        long expiryTime = arrivalTime + ttl;
+        final long ttl = 10000;
+        final long arrivalTime = System.currentTimeMillis();
+        final long expiryTime = arrivalTime + ttl;
         final Header header = new Header();
         header.setTtl(UnsignedInteger.valueOf(ttl));
 
-        Message_1_0 originalMessage = createTestMessage(header, arrivalTime);
+        final Message_1_0 originalMessage = createTestMessage(header, arrivalTime);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(expiryTime, convertedMessage.getMessageHeader().getExpiration(), "Unexpected expiration");
     }
 
     @Test
-    public void testContentEncodingConversion()
+    void contentEncodingConversion()
     {
-        String contentEncoding = "my-test-encoding";
+        final String contentEncoding = "my-test-encoding";
         final Properties properties = new Properties();
         properties.setContentEncoding(Symbol.valueOf(contentEncoding));
-        Message_1_0 originalMessage = createTestMessage(properties);
+        final Message_1_0 originalMessage = createTestMessage(properties);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(contentEncoding, convertedMessage.getMessageHeader().getEncoding(), "Unexpected content encoding");
-
     }
 
     @Test
-    public void testMessageIdStringConversion()
+    void messageIdStringConversion()
     {
         final String messageId = "testMessageId";
-        Properties properties = new Properties();
+        final Properties properties = new Properties();
         properties.setMessageId(messageId);
-        Message_1_0 originalMessage = createTestMessage(properties);
+        final Message_1_0 originalMessage = createTestMessage(properties);
 
         InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
@@ -168,163 +166,163 @@
     }
 
     @Test
-    public void testMessageIdUuidConversion()
+    void messageIdUuidConversion()
     {
         final UUID messageId = UUID.randomUUID();
-        Properties properties = new Properties();
+        final Properties properties = new Properties();
         properties.setMessageId(messageId);
-        Message_1_0 originalMessage = createTestMessage(properties);
+        final Message_1_0 originalMessage = createTestMessage(properties);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(messageId.toString(), convertedMessage.getMessageHeader().getMessageId(), "Unexpected messageId");
     }
 
     @Test
-    public void testMessageIdUnsignedLongConversion()
+    void messageIdUnsignedLongConversion()
     {
         final UnsignedLong messageId = UnsignedLong.valueOf(-1L);
-        Properties properties = new Properties();
+        final Properties properties = new Properties();
         properties.setMessageId(messageId);
-        Message_1_0 originalMessage = createTestMessage(properties);
+        final Message_1_0 originalMessage = createTestMessage(properties);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(messageId.toString(), convertedMessage.getMessageHeader().getMessageId(), "Unexpected messageId");
     }
 
     @Test
-    public void testMessageIdBinaryConversion()
+    void messageIdBinaryConversion()
     {
         final byte[] data = new byte[]{(byte) 0xc3, 0x28};
         final Binary messageId = new Binary(data);
-        Properties properties = new Properties();
+        final Properties properties = new Properties();
         properties.setMessageId(messageId);
-        Message_1_0 originalMessage = createTestMessage(properties);
+        final Message_1_0 originalMessage = createTestMessage(properties);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(messageId.toString(), convertedMessage.getMessageHeader().getMessageId(), "Unexpected messageId");
     }
 
     @Test
-    public void testCorrelationIdStringConversion()
+    void correlationIdStringConversion()
     {
         final String correlationId = "testMessageCorrelationId";
-        Properties properties = new Properties();
+        final Properties properties = new Properties();
         properties.setCorrelationId(correlationId);
-        Message_1_0 originalMessage = createTestMessage(properties);
+        final Message_1_0 originalMessage = createTestMessage(properties);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(correlationId, convertedMessage.getMessageHeader().getCorrelationId(), "Unexpected correlationId");
     }
 
     @Test
-    public void testCorrelationIdUuidConversion()
+    void correlationIdUuidConversion()
     {
         final UUID correlationId = UUID.randomUUID();
-        Properties properties = new Properties();
+        final Properties properties = new Properties();
         properties.setCorrelationId(correlationId);
-        Message_1_0 originalMessage = createTestMessage(properties);
+        final Message_1_0 originalMessage = createTestMessage(properties);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(correlationId.toString(), convertedMessage.getMessageHeader().getCorrelationId(), "Unexpected correlationId");
     }
 
     @Test
-    public void testCorrelationIdUnsignedLongConversion()
+    void correlationIdUnsignedLongConversion()
     {
         final UnsignedLong correlationId = UnsignedLong.valueOf(-1L);
-        Properties properties = new Properties();
+        final Properties properties = new Properties();
         properties.setCorrelationId(correlationId);
-        Message_1_0 originalMessage = createTestMessage(properties);
+        final Message_1_0 originalMessage = createTestMessage(properties);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(correlationId.toString(), convertedMessage.getMessageHeader().getCorrelationId(), "Unexpected correlationId");
     }
 
     @Test
-    public void testCorrelationIdBinaryConversion()
+    void correlationIdBinaryConversion()
     {
         final byte[] data = new byte[]{(byte) 0xc3, 0x28};
         final Binary correlationId = new Binary(data);
-        Properties properties = new Properties();
+        final Properties properties = new Properties();
         properties.setCorrelationId(correlationId);
-        Message_1_0 originalMessage = createTestMessage(properties);
+        final Message_1_0 originalMessage = createTestMessage(properties);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(correlationId.toString(), convertedMessage.getMessageHeader().getCorrelationId(), "Unexpected correlationId");
     }
 
     @Test
-    public void testUserIdConversion()
+    void userIdConversion()
     {
         final byte[] data = new byte[]{(byte) 0xc3, 0x28};
         final Binary userId = new Binary(data);
-        Properties properties = new Properties();
+        final Properties properties = new Properties();
         properties.setUserId(userId);
-        Message_1_0 originalMessage = createTestMessage(properties);
+        final Message_1_0 originalMessage = createTestMessage(properties);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(new String(data, UTF_8), convertedMessage.getMessageHeader().getUserId(), "Unexpected userId");
     }
 
     @Test
-    public void testReplyToConversion()
+    void replyToConversion()
     {
         final String replyTo = "amq.direct/test";
-        Properties properties = new Properties();
+        final Properties properties = new Properties();
         properties.setReplyTo(replyTo);
-        Message_1_0 originalMessage = createTestMessage(properties);
+        final Message_1_0 originalMessage = createTestMessage(properties);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(replyTo, convertedMessage.getMessageHeader().getReplyTo(), "Unexpected replyTo");
     }
 
     @Test
-    public void testCreationTimeConversion()
+    void creationTimeConversion()
     {
         final long creationTime = System.currentTimeMillis();
-        Properties properties = new Properties();
+        final Properties properties = new Properties();
         properties.setCreationTime(new Date(creationTime));
-        Message_1_0 originalMessage = createTestMessage(properties);
+        final Message_1_0 originalMessage = createTestMessage(properties);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(creationTime, convertedMessage.getMessageHeader().getTimestamp(), "Unexpected timestamp");
     }
 
     @Test
-    public void testToConversionIntoToAndInitialRoutingAddressWhenToIncludesExchangeNameAndRoutingKey()
+    void toConversionIntoToAndInitialRoutingAddressWhenToIncludesExchangeNameAndRoutingKey()
     {
         final String exchangeName = "amq.direct";
         final String routingKey = "test";
         final String to = String.format("%s/%s", exchangeName, routingKey);
-        Properties properties = new Properties();
+        final Properties properties = new Properties();
         properties.setTo(to);
-        Message_1_0 originalMessage = createTestMessage(properties);
+        final Message_1_0 originalMessage = createTestMessage(properties);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(to, convertedMessage.getTo(), "Unexpected to");
         assertEquals("", convertedMessage.getInitialRoutingAddress(), "Unexpected initialRoutingAddress");
     }
 
     @Test
-    public void testApplicationPropertiesConversion()
+    void applicationPropertiesConversion()
     {
-        Map<String, Object> properties = new HashMap<>();
+        final Map<String, Object> properties = new HashMap<>();
         properties.put("testProperty1", "testProperty1Value");
         properties.put("intProperty", 1);
         properties.put("nullProperty", null);
-        ApplicationProperties applicationProperties = new ApplicationProperties(properties);
-        Message_1_0 originalMessage = createTestMessage(applicationProperties);
+        final ApplicationProperties applicationProperties = new ApplicationProperties(properties);
+        final Message_1_0 originalMessage = createTestMessage(applicationProperties);
 
         final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
@@ -332,7 +330,6 @@
         assertEquals(properties, new HashMap<>(headers), "Unexpected headers");
     }
 
-
     private Message_1_0 createTestMessage(final Header header)
     {
         return createTestMessage(header, 0);
@@ -340,13 +337,8 @@
 
     private Message_1_0 createTestMessage(final Header header, long arrivalTime)
     {
-        return createTestMessage(header,
-                                 new DeliveryAnnotations(Collections.emptyMap()),
-                                 new MessageAnnotations(Collections.emptyMap()),
-                                 new Properties(),
-                                 new ApplicationProperties(Collections.emptyMap()),
-                                 arrivalTime,
-                                 null);
+        return createTestMessage(header, new DeliveryAnnotations(Map.of()), new MessageAnnotations(Map.of()),
+                new Properties(), new ApplicationProperties(Map.of()), arrivalTime, null);
     }
 
     private Message_1_0 createTestMessage(final Properties properties)
@@ -356,24 +348,14 @@
 
     private Message_1_0 createTestMessage(final Properties properties, final long arrivalTime)
     {
-        return createTestMessage(new Header(),
-                                 new DeliveryAnnotations(Collections.emptyMap()),
-                                 new MessageAnnotations(Collections.emptyMap()),
-                                 properties,
-                                 new ApplicationProperties(Collections.emptyMap()),
-                                 arrivalTime,
-                                 null);
+        return createTestMessage(new Header(), new DeliveryAnnotations(Map.of()), new MessageAnnotations(Map.of()),
+                properties, new ApplicationProperties(Map.of()), arrivalTime, null);
     }
 
     private Message_1_0 createTestMessage(final ApplicationProperties applicationProperties)
     {
-        return createTestMessage(new Header(),
-                                 new DeliveryAnnotations(Collections.emptyMap()),
-                                 new MessageAnnotations(Collections.emptyMap()),
-                                 new Properties(),
-                                 applicationProperties,
-                                 0,
-                                 null);
+        return createTestMessage(new Header(), new DeliveryAnnotations(Map.of()), new MessageAnnotations(Map.of()),
+                new Properties(), applicationProperties, 0, null);
     }
 
     private Message_1_0 createTestMessage(final Header header,
@@ -385,22 +367,22 @@
                                           final byte[] content)
     {
         final StoredMessage<MessageMetaData_1_0> storedMessage = mock(StoredMessage.class);
-        MessageMetaData_1_0 metaData = new MessageMetaData_1_0(header.createEncodingRetainingSection(),
-                                                               deliveryAnnotations.createEncodingRetainingSection(),
-                                                               messageAnnotations.createEncodingRetainingSection(),
-                                                               properties.createEncodingRetainingSection(),
-                                                               applicationProperties.createEncodingRetainingSection(),
-                                                               new Footer(Collections.emptyMap()).createEncodingRetainingSection(),
-                                                               arrivalTime,
-                                                               content == null ? 0 : content.length);
+        final MessageMetaData_1_0 metaData = new MessageMetaData_1_0(header.createEncodingRetainingSection(),
+                deliveryAnnotations.createEncodingRetainingSection(),
+                messageAnnotations.createEncodingRetainingSection(),
+                properties.createEncodingRetainingSection(),
+                applicationProperties.createEncodingRetainingSection(),
+                new Footer(Map.of()).createEncodingRetainingSection(),
+                arrivalTime,
+                content == null ? 0 : content.length);
         when(storedMessage.getMetaData()).thenReturn(metaData);
 
         if (content != null)
         {
-            Binary binary = new Binary(content);
-            DataSection dataSection = new Data(binary).createEncodingRetainingSection();
-            QpidByteBuffer qbb = dataSection.getEncodedForm();
-            int length = qbb.remaining();
+            final Binary binary = new Binary(content);
+            final DataSection dataSection = new Data(binary).createEncodingRetainingSection();
+            final QpidByteBuffer qbb = dataSection.getEncodedForm();
+            final int length = qbb.remaining();
             when(storedMessage.getContentSize()).thenReturn(length);
             when(storedMessage.getContent(0, length)).thenReturn(qbb);
         }
diff --git a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/ProtocolEngine_1_0_0Test.java b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/ProtocolEngine_1_0_0Test.java
index 0d0668b..f51f4b8 100644
--- a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/ProtocolEngine_1_0_0Test.java
+++ b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/ProtocolEngine_1_0_0Test.java
@@ -33,9 +33,9 @@
 
 import java.net.InetSocketAddress;
 import java.security.Principal;
-import java.util.Arrays;
-import java.util.Collections;
+import java.util.List;
 import java.util.Map;
+import java.util.Set;
 import java.util.UUID;
 
 import javax.security.auth.Subject;
@@ -79,19 +79,20 @@
 import org.apache.qpid.server.virtualhost.VirtualHostPrincipal;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class ProtocolEngine_1_0_0Test extends UnitTestBase
+@SuppressWarnings({"rawtypes"})
+class ProtocolEngine_1_0_0Test extends UnitTestBase
 {
     private AMQPConnection_1_0Impl _protocolEngine_1_0_0;
     private ServerNetworkConnection _networkConnection;
     private Broker<?> _broker;
     private AmqpPort _port;
-    private AuthenticationProvider _authenticationProvider;
+    private AuthenticationProvider<?> _authenticationProvider;
     private FrameWriter _frameWriter;
-    private AMQPConnection _connection;
+    private AMQPConnection<?> _connection;
     private VirtualHost<?> _virtualHost;
 
     @BeforeEach
-    public void setUp() throws Exception
+    void setUp()
     {
         _networkConnection = mock(ServerNetworkConnection.class);
         when(_networkConnection.getLocalAddress()).thenReturn(new InetSocketAddress(0));
@@ -124,7 +125,7 @@
         doAnswer(invocation ->
         {
             _connection = connectionCaptor.getValue();
-            throw new SoleConnectionEnforcementPolicyException(null, Collections.emptySet(), "abc1");
+            throw new SoleConnectionEnforcementPolicyException(null, Set.of(), "abc1");
         }).when(_virtualHost).registerConnection(connectionCaptor.capture());
         when(_virtualHost.getPrincipal()).thenReturn(mock(VirtualHostPrincipal.class));
         when(_port.getAddressSpace(anyString())).thenReturn(_virtualHost);
@@ -133,7 +134,7 @@
         final ArgumentCaptor<Principal> userCaptor = ArgumentCaptor.forClass(Principal.class);
         when(subjectCreator.createSubjectWithGroups(userCaptor.capture())).then((Answer<Subject>) invocation ->
         {
-            Subject subject = new Subject();
+            final Subject subject = new Subject();
             subject.getPrincipals().add(userCaptor.getValue());
             return subject;
         });
@@ -141,44 +142,43 @@
         final ByteBufferSender sender = mock(ByteBufferSender.class);
         when(_networkConnection.getSender()).thenReturn(sender);
 
-        AMQPDescribedTypeRegistry registry = AMQPDescribedTypeRegistry.newInstance().registerTransportLayer()
+        final AMQPDescribedTypeRegistry registry = AMQPDescribedTypeRegistry.newInstance().registerTransportLayer()
                 .registerMessagingLayer()
                 .registerTransactionLayer()
                 .registerSecurityLayer();
 
         _frameWriter = new FrameWriter(registry, new ByteBufferSender()
-                                                {
+        {
+            @Override
+            public boolean isDirectBufferPreferred()
+            {
+                return false;
+            }
 
-                                                    @Override
-                                                    public boolean isDirectBufferPreferred()
-                                                    {
-                                                        return false;
-                                                    }
+            @Override
+            public void send(final QpidByteBuffer msg)
+            {
+                _protocolEngine_1_0_0.received(msg);
+            }
 
-                                                    @Override
-                                                    public void send(final QpidByteBuffer msg)
-                                                    {
-                                                        _protocolEngine_1_0_0.received(msg);
-                                                    }
+            @Override
+            public void flush()
+            {
 
-                                                    @Override
-                                                    public void flush()
-                                                    {
+            }
 
-                                                    }
+            @Override
+            public void close()
+            {
 
-                                                    @Override
-                                                    public void close()
-                                                    {
-
-                                                    }
-                                                });
+            }
+        });
     }
 
     @Test
-    public void testProtocolEngineWithNoSaslNonTLSandAnon()
+    void protocolEngineWithNoSaslNonTLSandAnon()
     {
-        final Map<String, Object> attrs = Collections.singletonMap(ConfiguredObject.NAME, getTestName());
+        final Map<String, Object> attrs = Map.of(ConfiguredObject.NAME, getTestName());
         final AnonymousAuthenticationManager anonymousAuthenticationManager =
                 (new AnonymousAuthenticationManagerFactory()).create(null, attrs, _broker);
         when(_port.getAuthenticationProvider()).thenReturn(anonymousAuthenticationManager);
@@ -187,21 +187,20 @@
         createEngine(Transport.TCP);
 
         _protocolEngine_1_0_0.received(QpidByteBuffer.wrap(ProtocolEngineCreator_1_0_0.getInstance()
-                                                                   .getHeaderIdentifier()));
+                .getHeaderIdentifier()));
 
-        Open open = new Open();
+        final Open open = new Open();
         open.setContainerId("testContainerId");
-        _frameWriter.send(new TransportFrame((int) (short) 0, open));
+        _frameWriter.send(new TransportFrame((short) 0, open));
 
         verify(_virtualHost).registerConnection(any(AMQPConnection.class));
-        AuthenticatedPrincipal principal = (AuthenticatedPrincipal) _connection.getAuthorizedPrincipal();
+        final AuthenticatedPrincipal principal = (AuthenticatedPrincipal) _connection.getAuthorizedPrincipal();
         assertNotNull(principal);
         assertEquals(principal, new AuthenticatedPrincipal(anonymousAuthenticationManager.getAnonymousPrincipal()));
-
     }
 
     @Test
-    public void testProtocolEngineWithNoSaslNonTLSandNoAnon()
+    void protocolEngineWithNoSaslNonTLSandNoAnon()
     {
         allowMechanisms("foo");
 
@@ -209,16 +208,16 @@
 
         _protocolEngine_1_0_0.received(QpidByteBuffer.wrap(ProtocolEngineCreator_1_0_0.getInstance().getHeaderIdentifier()));
 
-        Open open = new Open();
+        final Open open = new Open();
         open.setContainerId("testContainerId");
-        _frameWriter.send(new TransportFrame((int) (short) 0, open));
+        _frameWriter.send(new TransportFrame((short) 0, open));
 
         verify(_virtualHost, never()).registerConnection(any(AMQPConnection.class));
         verify(_networkConnection).close();
     }
 
     @Test
-    public void testProtocolEngineWithNoSaslTLSandExternal()
+    void protocolEngineWithNoSaslTLSandExternal()
     {
         final Principal principal = () -> "test";
         when(_networkConnection.getPeerPrincipal()).thenReturn(principal);
@@ -228,58 +227,58 @@
         createEngine(Transport.SSL);
         _protocolEngine_1_0_0.received(QpidByteBuffer.wrap(ProtocolEngineCreator_1_0_0.getInstance().getHeaderIdentifier()));
 
-        Open open = new Open();
+        final Open open = new Open();
         open.setContainerId("testContainerId");
-        _frameWriter.send(new TransportFrame((int) (short) 0, open));
+        _frameWriter.send(new TransportFrame((short) 0, open));
 
         verify(_virtualHost).registerConnection(any(AMQPConnection.class));
-        AuthenticatedPrincipal authPrincipal = (AuthenticatedPrincipal) _connection.getAuthorizedPrincipal();
+        final AuthenticatedPrincipal authPrincipal = (AuthenticatedPrincipal) _connection.getAuthorizedPrincipal();
         assertNotNull(authPrincipal);
         assertEquals(authPrincipal, new AuthenticatedPrincipal(principal));
     }
 
     @Test
-    public void testProtocolEngineWithSaslNonTLSandAnon()
+    void protocolEngineWithSaslNonTLSandAnon()
     {
-        final Map<String, Object> attrs = Collections.singletonMap(ConfiguredObject.NAME, getTestName());
+        final Map<String, Object> attrs = Map.of(ConfiguredObject.NAME, getTestName());
         final AnonymousAuthenticationManager anonymousAuthenticationManager =
                 (new AnonymousAuthenticationManagerFactory()).create(null, attrs, _broker);
         when(_port.getAuthenticationProvider()).thenReturn(anonymousAuthenticationManager);
-        when(_port.getSubjectCreator(anyBoolean(), anyString())).thenReturn(new SubjectCreator(anonymousAuthenticationManager, Collections.emptyList(), null));
+        when(_port.getSubjectCreator(anyBoolean(), anyString()))
+                .thenReturn(new SubjectCreator(anonymousAuthenticationManager, List.of(), null));
 
         allowMechanisms(AnonymousAuthenticationManager.MECHANISM_NAME);
 
         createEngine(Transport.TCP);
 
         _protocolEngine_1_0_0.received(QpidByteBuffer.wrap(ProtocolEngineCreator_1_0_0_SASL.getInstance()
-                                                                   .getHeaderIdentifier()));
+                .getHeaderIdentifier()));
 
-        SaslInit init = new SaslInit();
+        final SaslInit init = new SaslInit();
         init.setMechanism(Symbol.valueOf("ANONYMOUS"));
         _frameWriter.send(new SASLFrame(init));
 
         _protocolEngine_1_0_0.received(QpidByteBuffer.wrap(ProtocolEngineCreator_1_0_0.getInstance()
-                                                                   .getHeaderIdentifier()));
+                .getHeaderIdentifier()));
 
-        Open open = new Open();
+        final Open open = new Open();
         open.setContainerId("testContainerId");
-        _frameWriter.send(new TransportFrame((int) (short) 0, open));
+        _frameWriter.send(new TransportFrame((short) 0, open));
 
         verify(_virtualHost).registerConnection(any(AMQPConnection.class));
-        AuthenticatedPrincipal principal = (AuthenticatedPrincipal) _connection.getAuthorizedPrincipal();
+        final AuthenticatedPrincipal principal = (AuthenticatedPrincipal) _connection.getAuthorizedPrincipal();
         assertNotNull(principal);
         assertEquals(principal, new AuthenticatedPrincipal(anonymousAuthenticationManager.getAnonymousPrincipal()));
     }
 
-
-    private void createEngine(Transport transport)
+    private void createEngine(final Transport transport)
     {
         _protocolEngine_1_0_0 =
                 new AMQPConnection_1_0Impl(_broker, _networkConnection, _port, transport, 1, new AggregateTicker());
     }
 
-    private void allowMechanisms(String... mechanisms)
+    private void allowMechanisms(final String... mechanisms)
     {
-        when(_authenticationProvider.getAvailableMechanisms(anyBoolean())).thenReturn(Arrays.asList(mechanisms));
+        when(_authenticationProvider.getAvailableMechanisms(anyBoolean())).thenReturn(List.of(mechanisms));
     }
 }
diff --git a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/SendingLinkEndpointTest.java b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/SendingLinkEndpointTest.java
index 269533d..811737f 100644
--- a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/SendingLinkEndpointTest.java
+++ b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/SendingLinkEndpointTest.java
@@ -45,20 +45,21 @@
 import org.apache.qpid.server.protocol.v1_0.type.transport.Role;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class SendingLinkEndpointTest extends UnitTestBase
+@SuppressWarnings({"rawtypes", "unchecked"})
+class SendingLinkEndpointTest extends UnitTestBase
 {
     private static final String ADDRESS = "test";
 
     private SendingLinkEndpoint _sendingLinkEndpoint;
 
     @BeforeAll
-    public void setUp() throws Exception
+    void setUp() throws Exception
     {
-        NamedAddressSpace addressSpace = mock(NamedAddressSpace.class);
+        final NamedAddressSpace addressSpace = mock(NamedAddressSpace.class);
 
         final LinkImpl<Source, Target> link = mock(LinkImpl.class);
         when(link.getSource()).thenReturn(new Source());
-        Target target = new Target();
+        final Target target = new Target();
         target.setAddress(ADDRESS);
         when(link.getTarget()).thenReturn(target);
 
@@ -75,31 +76,31 @@
     }
 
     @Test
-    public void receiveFlow() throws Exception
+    void receiveFlow() throws Exception
     {
         receiveAttach(_sendingLinkEndpoint);
 
         _sendingLinkEndpoint.setDeliveryCount(new SequenceNumber(-1));
 
-        Flow flow = new Flow();
+        final Flow flow = new Flow();
         flow.setDeliveryCount(new SequenceNumber(-1).unsignedIntegerValue());
         flow.setLinkCredit(UnsignedInteger.ONE);
 
         _sendingLinkEndpoint.receiveFlow(flow);
 
-        UnsignedInteger linkCredit = _sendingLinkEndpoint.getLinkCredit();
+        final UnsignedInteger linkCredit = _sendingLinkEndpoint.getLinkCredit();
         assertThat(linkCredit, is(equalTo(UnsignedInteger.ONE)));
     }
 
     private void receiveAttach(final SendingLinkEndpoint sendingLinkEndpoint) throws Exception
     {
-        Attach attach = new Attach();
-        Source source = new Source();
+        final Attach attach = new Attach();
+        final Source source = new Source();
         source.setDurable(TerminusDurability.NONE);
         source.setExpiryPolicy(TerminusExpiryPolicy.LINK_DETACH);
 
         attach.setSource(source);
-        Target target = new Target();
+        final Target target = new Target();
         attach.setTarget(target);
         attach.setHandle(new UnsignedInteger(0));
         attach.setIncompleteUnsettled(false);
diff --git a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/Session_1_0Test.java b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/Session_1_0Test.java
index 11fe946..1bc14cd 100644
--- a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/Session_1_0Test.java
+++ b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/Session_1_0Test.java
@@ -34,10 +34,9 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
-import java.util.Collections;
-import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 import java.util.UUID;
 
 import javax.security.auth.Subject;
@@ -52,6 +51,7 @@
 import org.mockito.stubbing.Answer;
 
 import org.apache.qpid.server.configuration.updater.CurrentThreadTaskExecutor;
+import org.apache.qpid.server.configuration.updater.TaskExecutor;
 import org.apache.qpid.server.filter.AMQPFilterTypes;
 import org.apache.qpid.server.logging.EventLogger;
 import org.apache.qpid.server.model.Binding;
@@ -88,51 +88,51 @@
 import org.apache.qpid.server.virtualhost.TestMemoryVirtualHost;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class Session_1_0Test extends UnitTestBase
+@SuppressWarnings({"rawtypes", "unchecked"})
+class Session_1_0Test extends UnitTestBase
 {
     private static final AMQPDescribedTypeRegistry DESCRIBED_TYPE_REGISTRY = AMQPDescribedTypeRegistry.newInstance()
-                                                                                                      .registerTransportLayer()
-                                                                                                      .registerMessagingLayer()
-                                                                                                      .registerTransactionLayer()
-                                                                                                      .registerSecurityLayer()
-                                                                                                      .registerExtensionSoleconnLayer();
+            .registerTransportLayer()
+            .registerMessagingLayer()
+            .registerTransactionLayer()
+            .registerSecurityLayer()
+            .registerExtensionSoleconnLayer();
 
     private static final String TOPIC_NAME = "testTopic";
     private static final String QUEUE_NAME = "testQueue";
     private static final Symbol TOPIC_CAPABILITY = Symbol.getSymbol("topic");
     private static final Symbol QUEUE_CAPABILITY = Symbol.getSymbol("queue");
     private static final Symbol JMS_SELECTOR_FILTER = Symbol.getSymbol("jms-selector");
-    private AMQPConnection_1_0 _connection;
+
+    private AMQPConnection_1_0<?> _connection;
     private VirtualHost<?> _virtualHost;
     private Session_1_0 _session;
     private int _handle;
-    private CurrentThreadTaskExecutor _taskExecutor;
+    private TaskExecutor _taskExecutor;
 
     @BeforeEach
-    public void setUp() throws Exception
+    void setUp()
     {
-        Map<String, Object> virtualHostAttributes = new HashMap<>();
-        virtualHostAttributes.put(QueueManagingVirtualHost.NAME, "testVH");
-        virtualHostAttributes.put(QueueManagingVirtualHost.TYPE, TestMemoryVirtualHost.VIRTUAL_HOST_TYPE);
+        final Map<String, Object> virtualHostAttributes = Map.of(QueueManagingVirtualHost.NAME, "testVH",
+                QueueManagingVirtualHost.TYPE, TestMemoryVirtualHost.VIRTUAL_HOST_TYPE);
         _virtualHost = BrokerTestHelper.createVirtualHost(virtualHostAttributes, this);
-        _taskExecutor = new CurrentThreadTaskExecutor();
-        _taskExecutor.start();
+        _taskExecutor = CurrentThreadTaskExecutor.newStartedInstance();
         _connection = createAmqpConnection_1_0("testContainerId");
         this._session = createSession_1_0(_connection, 0);
     }
 
     @AfterEach
-    public void tearDown()
+    void tearDown()
     {
         _taskExecutor.stop();
     }
 
     @Test
-    public void testReceiveAttachTopicNonDurableNoContainer()
+    void receiveAttachTopicNonDurableNoContainer()
     {
         final String linkName = "testLink";
         final String address = "amq.direct/" + TOPIC_NAME;
-        Attach attach = createTopicAttach(false, linkName, address, true);
+        final Attach attach = createTopicAttach(false, linkName, address, true);
 
         _session.receiveAttach(attach);
 
@@ -141,11 +141,11 @@
     }
 
     @Test
-    public void testReceiveAttachTopicNonDurableWithContainer()
+    void receiveAttachTopicNonDurableWithContainer()
     {
         final String linkName = "testLink";
         final String address = "amq.direct/" + TOPIC_NAME;
-        Attach attach = createTopicAttach(false, linkName, address, false);
+        final Attach attach = createTopicAttach(false, linkName, address, false);
 
         _session.receiveAttach(attach);
 
@@ -154,11 +154,11 @@
     }
 
     @Test
-    public void testReceiveAttachTopicDurableNoContainer()
+    void receiveAttachTopicDurableNoContainer()
     {
         final String linkName = "testLink";
         final String address = "amq.direct/" + TOPIC_NAME;
-        Attach attach = createTopicAttach(true, linkName, address, true);
+        final Attach attach = createTopicAttach(true, linkName, address, true);
 
         _session.receiveAttach(attach);
 
@@ -167,24 +167,24 @@
     }
 
     @Test
-    public void testReceiveAttachTopicDurableWithContainer()
+    void receiveAttachTopicDurableWithContainer()
     {
         final String linkName = "testLink";
         final String address = "amq.direct/" + TOPIC_NAME;
-        Attach attach = createTopicAttach(true, linkName+ "|1", address, false);
+        final Attach attach = createTopicAttach(true, linkName+ "|1", address, false);
 
         _session.receiveAttach(attach);
 
         assertAttachSent(_connection, _session, attach);
         assertQueues(TOPIC_NAME, LifetimePolicy.PERMANENT);
 
-        AMQPConnection_1_0 secondConnection = createAmqpConnection_1_0("testContainerId2");
-        Session_1_0 secondSession = createSession_1_0(secondConnection, 0);
-        Attach attach2 = createTopicAttach(true, linkName + "|2", address, false);
+        final AMQPConnection_1_0<?> secondConnection = createAmqpConnection_1_0("testContainerId2");
+        final Session_1_0 secondSession = createSession_1_0(secondConnection, 0);
+        final Attach attach2 = createTopicAttach(true, linkName + "|2", address, false);
         secondSession.receiveAttach(attach2);
 
         assertAttachSent(secondConnection, secondSession, attach2);
-        Collection<Queue> queues = _virtualHost.getChildren(Queue.class);
+        final Collection<Queue> queues = _virtualHost.getChildren(Queue.class);
         assertEquals(2, (long) queues.size(),
                 "Unexpected number of queues after second subscription with the same subscription name but different " +
                 "container id ");
@@ -192,20 +192,20 @@
     }
 
     @Test
-    public void testReceiveAttachSharedTopicNonDurableNoContainer()
+    void receiveAttachSharedTopicNonDurableNoContainer()
     {
         final String linkName = "testLink";
         final String address = "amq.direct/" + TOPIC_NAME;
-        Attach attach = createSharedTopicAttach(false, linkName, address, true);
-        Attach attach2 = createSharedTopicAttach(false, linkName, address, true);
+        final Attach attach = createSharedTopicAttach(false, linkName, address, true);
+        final Attach attach2 = createSharedTopicAttach(false, linkName, address, true);
 
         _session.receiveAttach(attach);
 
         assertAttachSent(_connection, _session, attach);
         assertQueues(TOPIC_NAME, LifetimePolicy.DELETE_ON_NO_OUTBOUND_LINKS);
 
-        AMQPConnection_1_0 secondConnection = createAmqpConnection_1_0();
-        Session_1_0 secondSession = createSession_1_0(secondConnection, 0);
+        final AMQPConnection_1_0<?> secondConnection = createAmqpConnection_1_0();
+        final Session_1_0 secondSession = createSession_1_0(secondConnection, 0);
 
         secondSession.receiveAttach(attach2);
 
@@ -214,27 +214,27 @@
 
         final Collection<Queue> queues = _virtualHost.getChildren(Queue.class);
         assertEquals(1, (long) queues.size(), "Unexpected number of queues after attach");
-        Queue<?> queue = queues.iterator().next();
+        final Queue<?> queue = queues.iterator().next();
 
-        Collection<QueueConsumer<?,?>> consumers = queue.getConsumers();
+        final Collection<QueueConsumer<?,?>> consumers = queue.getConsumers();
         assertEquals(2, (long) consumers.size(), "Unexpected number of consumers");
     }
 
     @Test
-    public void testReceiveAttachSharedTopicNonDurableWithContainer()
+    void receiveAttachSharedTopicNonDurableWithContainer()
     {
         final String linkName = "testLink";
         final String address = "amq.direct/" + TOPIC_NAME;
-        Attach attach = createSharedTopicAttach(false, linkName, address, false);
-        Attach attach2 = createSharedTopicAttach(false, linkName, address, false);
+        final Attach attach = createSharedTopicAttach(false, linkName, address, false);
+        final Attach attach2 = createSharedTopicAttach(false, linkName, address, false);
 
         _session.receiveAttach(attach);
 
         assertAttachSent(_connection, _session, attach);
         assertQueues(TOPIC_NAME, LifetimePolicy.DELETE_ON_NO_OUTBOUND_LINKS);
 
-        AMQPConnection_1_0 secondConnection = createAmqpConnection_1_0("testContainerId2");
-        Session_1_0 secondSession = createSession_1_0(secondConnection, 0);
+        final AMQPConnection_1_0<?> secondConnection = createAmqpConnection_1_0("testContainerId2");
+        final Session_1_0 secondSession = createSession_1_0(secondConnection, 0);
 
         secondSession.receiveAttach(attach2);
 
@@ -243,24 +243,24 @@
         final Collection<Queue> queues = _virtualHost.getChildren(Queue.class);
         assertEquals(2, (long) queues.size(), "Unexpected number of queues after attach");
 
-        for (Queue<?> queue : queues)
+        for (final Queue<?> queue : queues)
         {
-            Collection<QueueConsumer<?,?>> consumers = queue.getConsumers();
+            final Collection<QueueConsumer<?,?>> consumers = queue.getConsumers();
             assertEquals(1, (long) consumers.size(),
                     "Unexpected number of consumers on queue " + queue.getName());
         }
     }
 
     @Test
-    public void testSeparateSubscriptionNameSpaces()
+    void separateSubscriptionNameSpaces()
     {
-        AMQPConnection_1_0 secondConnection = createAmqpConnection_1_0();
-        Session_1_0 secondSession = createSession_1_0(secondConnection, 0);
+        final AMQPConnection_1_0<?> secondConnection = createAmqpConnection_1_0();
+        final Session_1_0 secondSession = createSession_1_0(secondConnection, 0);
 
         final String linkName = "testLink";
         final String address = "amq.direct/" + TOPIC_NAME;
 
-        Attach durableSharedWithContainerId = createSharedTopicAttach(true, linkName + "|1", address, false);
+        final Attach durableSharedWithContainerId = createSharedTopicAttach(true, linkName + "|1", address, false);
         _session.receiveAttach(durableSharedWithContainerId);
         assertAttachSent(_connection, _session, durableSharedWithContainerId, 0);
 
@@ -268,7 +268,7 @@
         assertEquals(1, (long) queues.size(),
                 "Unexpected number of queues after durable non shared with containerId");
 
-        Attach durableNonSharedWithContainerId = createTopicAttach(true, linkName, address, false);
+        final Attach durableNonSharedWithContainerId = createTopicAttach(true, linkName, address, false);
         _session.receiveAttach(durableNonSharedWithContainerId);
         assertAttachFailed(_connection, _session, durableNonSharedWithContainerId, 1);
 
@@ -276,7 +276,7 @@
         assertEquals(1, (long) queues.size(),
                 "Unexpected number of queues after durable non shared with containerId");
 
-        Attach nonDurableSharedWithContainerId = createSharedTopicAttach(false, linkName + "|3", address, false);
+        final Attach nonDurableSharedWithContainerId = createSharedTopicAttach(false, linkName + "|3", address, false);
         _session.receiveAttach(nonDurableSharedWithContainerId);
         assertAttachSent(_connection, _session, nonDurableSharedWithContainerId, 3);
 
@@ -284,7 +284,7 @@
         assertEquals(2, (long) queues.size(),
                 "Unexpected number of queues after durable non shared with containerId");
 
-        Attach durableSharedWithoutContainerId = createSharedTopicAttach(true, linkName + "|4", address, true);
+        final Attach durableSharedWithoutContainerId = createSharedTopicAttach(true, linkName + "|4", address, true);
         secondSession.receiveAttach(durableSharedWithoutContainerId);
         assertAttachSent(secondConnection, secondSession, durableSharedWithoutContainerId, 0);
 
@@ -292,7 +292,7 @@
         assertEquals(3, (long) queues.size(),
                 "Unexpected number of queues after durable non shared with containerId");
 
-        Attach nonDurableSharedWithoutContainerId = createSharedTopicAttach(false, linkName + "|5", address, true);
+        final Attach nonDurableSharedWithoutContainerId = createSharedTopicAttach(false, linkName + "|5", address, true);
         secondSession.receiveAttach(nonDurableSharedWithoutContainerId);
         assertAttachSent(secondConnection, secondSession, nonDurableSharedWithoutContainerId, 1);
 
@@ -300,7 +300,7 @@
         assertEquals(4, (long) queues.size(),
                 "Unexpected number of queues after durable non shared with containerId");
 
-        Attach nonDurableNonSharedWithoutContainerId = createTopicAttach(false, linkName + "|6", address, true);
+        final Attach nonDurableNonSharedWithoutContainerId = createTopicAttach(false, linkName + "|6", address, true);
         secondSession.receiveAttach(nonDurableNonSharedWithoutContainerId);
         assertAttachSent(secondConnection, secondSession, nonDurableNonSharedWithoutContainerId, 2);
 
@@ -308,7 +308,7 @@
         assertEquals(5, (long) queues.size(),
                 "Unexpected number of queues after durable non shared with containerId");
 
-        Attach nonDurableNonSharedWithContainerId = createTopicAttach(false, linkName + "|6", address, false);
+        final Attach nonDurableNonSharedWithContainerId = createTopicAttach(false, linkName + "|6", address, false);
         _session.receiveAttach(nonDurableNonSharedWithContainerId);
         assertAttachSent(_connection, _session, nonDurableNonSharedWithContainerId, 4);
 
@@ -318,27 +318,27 @@
     }
 
     @Test
-    public void testReceiveAttachForInvalidUnsubscribe()
+    void receiveAttachForInvalidUnsubscribe()
     {
         final String linkName = "testLink";
         final String address = "amq.direct/" + TOPIC_NAME;
 
-        Attach unsubscribeAttach = createTopicAttach(true, linkName, address, false);
+        final Attach unsubscribeAttach = createTopicAttach(true, linkName, address, false);
         unsubscribeAttach.setSource(null);
 
         _session.receiveAttach(unsubscribeAttach);
         assertAttachFailed(_connection, _session, unsubscribeAttach);
 
-        Collection<Queue> queues = _virtualHost.getChildren(Queue.class);
+        final Collection<Queue> queues = _virtualHost.getChildren(Queue.class);
         assertEquals(0, (long) queues.size(), "Unexpected number of queues after unsubscribe");
     }
 
     @Test
-    public void testNullSourceLookup()
+    void nullSourceLookup()
     {
         final String linkName = "testLink";
         final String address = "amq.direct/" + TOPIC_NAME;
-        Attach attach = createTopicAttach(true, linkName, address, false);
+        final Attach attach = createTopicAttach(true, linkName, address, false);
 
         _session.receiveAttach(attach);
 
@@ -347,33 +347,32 @@
 
         sendDetach(_session, attach.getHandle(), false);
 
-        Attach nullSourceAttach = createTopicAttach(true, linkName, address, false);
+        final Attach nullSourceAttach = createTopicAttach(true, linkName, address, false);
         nullSourceAttach.setSource(null);
 
         _session.receiveAttach(nullSourceAttach);
-        ArgumentCaptor<FrameBody> frameCapture = ArgumentCaptor.forClass(FrameBody.class);
+        final ArgumentCaptor<FrameBody> frameCapture = ArgumentCaptor.forClass(FrameBody.class);
         verify(_connection, times(3)).sendFrame(eq(_session.getChannelId()), frameCapture.capture());
-        Attach sentAttach = (Attach) frameCapture.getAllValues().get(2);
+        final Attach sentAttach = (Attach) frameCapture.getAllValues().get(2);
 
         assertEquals(nullSourceAttach.getName(), sentAttach.getName(), "Unexpected name");
         assertEquals(Role.SENDER, sentAttach.getRole(), "Unexpected role");
         assertNotNull(sentAttach.getSource(), "Unexpected source");
-        Source source = (Source)sentAttach.getSource();
+        final Source source = (Source)sentAttach.getSource();
         assertEquals(address, source.getAddress(), "Unexpected address");
         assertTrue(Arrays.asList(source.getCapabilities()).contains(Symbol.valueOf("topic")),
                 "Unexpected source capabilities");
 
-
-        Collection<Queue> queues = _virtualHost.getChildren(Queue.class);
+        final Collection<Queue> queues = _virtualHost.getChildren(Queue.class);
         assertEquals(1, (long) queues.size(), "Unexpected number of queues after unsubscribe");
     }
 
     @Test
-    public void testReceiveDetachClosed()
+    void receiveDetachClosed()
     {
         final String linkName = "testLink";
         final String address = "amq.direct/" + TOPIC_NAME;
-        Attach attach = createTopicAttach(true, linkName, address, false);
+        final Attach attach = createTopicAttach(true, linkName, address, false);
 
         _session.receiveAttach(attach);
 
@@ -382,19 +381,19 @@
 
         sendDetach(_session, attach.getHandle(), true);
 
-        Collection<Queue> queues = _virtualHost.getChildren(Queue.class);
+        final Collection<Queue> queues = _virtualHost.getChildren(Queue.class);
         assertEquals(0, (long) queues.size(), "Unexpected number of queues after unsubscribe");
     }
 
     @Test
-    public void testReceiveAttachToExistingQueue()
+    void receiveAttachToExistingQueue()
     {
         final String linkName = "testLink";
-        Attach attach = createQueueAttach(false, linkName, QUEUE_NAME);
+        final Attach attach = createQueueAttach(false, linkName, QUEUE_NAME);
 
-        Queue<?> queue = _virtualHost.createChild(Queue.class, Collections.singletonMap(Queue.NAME, QUEUE_NAME));
-        Exchange<?> exchange = _virtualHost.getChildByName(Exchange.class, "amq.direct");
-        exchange.bind(QUEUE_NAME, QUEUE_NAME, Collections.emptyMap(), false);
+        final Queue<?> queue = _virtualHost.createChild(Queue.class, Map.of(Queue.NAME, QUEUE_NAME));
+        final Exchange<?> exchange = _virtualHost.getChildByName(Exchange.class, "amq.direct");
+        exchange.bind(QUEUE_NAME, QUEUE_NAME, Map.of(), false);
 
         _session.receiveAttach(attach);
 
@@ -402,20 +401,20 @@
     }
 
     @Test
-    public void testReceiveAttachToNonExistingQueue()
+    void receiveAttachToNonExistingQueue()
     {
         final String linkName = "testLink";
-        Attach attach = createQueueAttach(false, linkName, QUEUE_NAME);
+        final Attach attach = createQueueAttach(false, linkName, QUEUE_NAME);
         _session.receiveAttach(attach);
         assertAttachFailed(_connection, _session, attach);
     }
 
     @Test
-    public void testReceiveAttachRebindingQueueNoActiveLinks()
+    void receiveAttachRebindingQueueNoActiveLinks()
     {
         final String linkName = "testLink";
         final String address = "amq.direct/" + TOPIC_NAME;
-        Attach attach = createSharedTopicAttach(true, linkName, address, true);
+        final Attach attach = createSharedTopicAttach(true, linkName, address, true);
         _session.receiveAttach(attach);
 
         assertAttachSent(_connection, _session, attach);
@@ -423,16 +422,16 @@
 
         sendDetach(_session, attach.getHandle(), false);
 
-        ArgumentCaptor<FrameBody> frameCapture = ArgumentCaptor.forClass(FrameBody.class);
+        final ArgumentCaptor<FrameBody> frameCapture = ArgumentCaptor.forClass(FrameBody.class);
         verify(_connection, times(2)).sendFrame(eq(_session.getChannelId()), frameCapture.capture());
         final boolean condition = frameCapture.getAllValues().get(1) instanceof Detach;
         assertTrue(condition);
 
         assertQueues(TOPIC_NAME, LifetimePolicy.PERMANENT);
 
-        String topicName2 = TOPIC_NAME + "2";
+        final String topicName2 = TOPIC_NAME + "2";
         final String address2 = "amq.direct/" + topicName2;
-        Attach attach2 = createSharedTopicAttach(true, linkName + "|2", address2, true);
+        final Attach attach2 = createSharedTopicAttach(true, linkName + "|2", address2, true);
 
         _session.receiveAttach(attach2);
         assertAttachSent(_connection, _session, attach2, 2);
@@ -441,11 +440,11 @@
     }
 
     @Test
-    public void testReceiveReattachRebindingQueueNoActiveLinks()
+    void receiveReattachRebindingQueueNoActiveLinks()
     {
         final String linkName = "testLink";
         final String address = "amq.direct/" + TOPIC_NAME;
-        Attach attach = createSharedTopicAttach(true, linkName, address, true);
+        final Attach attach = createSharedTopicAttach(true, linkName, address, true);
         _session.receiveAttach(attach);
 
         assertAttachSent(_connection, _session, attach);
@@ -453,16 +452,16 @@
 
         sendDetach(_session, attach.getHandle(), false);
 
-        ArgumentCaptor<FrameBody> frameCapture = ArgumentCaptor.forClass(FrameBody.class);
+        final ArgumentCaptor<FrameBody> frameCapture = ArgumentCaptor.forClass(FrameBody.class);
         verify(_connection, times(2)).sendFrame(eq(_session.getChannelId()), frameCapture.capture());
         final boolean condition = frameCapture.getAllValues().get(1) instanceof Detach;
         assertTrue(condition);
 
         assertQueues(TOPIC_NAME, LifetimePolicy.PERMANENT);
 
-        String topicName2 = TOPIC_NAME + "2";
+        final String topicName2 = TOPIC_NAME + "2";
         final String address2 = "amq.direct/" + topicName2;
-        Attach attach2 = createSharedTopicAttach(true, linkName, address2, true);
+        final Attach attach2 = createSharedTopicAttach(true, linkName, address2, true);
 
         _session.receiveAttach(attach2);
         assertAttachSent(_connection, _session, attach2, 2);
@@ -471,32 +470,32 @@
     }
 
     @Test
-    public void testReceiveAttachTopicNonDurableNoContainerWithInvalidSelector()
+    void receiveAttachTopicNonDurableNoContainerWithInvalidSelector()
     {
         final String linkName = "testLink";
         final String address = "amq.direct/" + TOPIC_NAME;
-        Attach attach = createTopicAttach(false, linkName, address, true);
+        final Attach attach = createTopicAttach(false, linkName, address, true);
         setSelector(attach, "invalid selector");
 
         _session.receiveAttach(attach);
 
         assertAttachFailed(_connection, _session, attach);
         final Collection<Queue> queues = _virtualHost.getChildren(Queue.class);
-        assertEquals((long) 0, (long) queues.size(), "Unexpected number of queues after attach");
+        assertEquals(0, (long) queues.size(), "Unexpected number of queues after attach");
     }
 
     @Test
-    public void testReceiveAttachTopicNonDurableNoContainerWithValidSelector()
+    void receiveAttachTopicNonDurableNoContainerWithValidSelector()
     {
         final String linkName = "testLink";
         final String address = "amq.direct/" + TOPIC_NAME;
         final String selectorExpression = "test='test'";
-        Attach attach = createTopicAttach(false, linkName, address, true);
+        final Attach attach = createTopicAttach(false, linkName, address, true);
         setSelector(attach, selectorExpression);
 
         _session.receiveAttach(attach);
 
-        Attach sentAttach = captureAttach(_connection, _session, 0);
+        final Attach sentAttach = captureAttach(_connection, _session, 0);
 
         assertEquals(attach.getName(), sentAttach.getName(), "Unexpected name");
         assertEquals(Role.SENDER, sentAttach.getRole(), "Unexpected role");
@@ -504,30 +503,30 @@
 
         assertQueues(TOPIC_NAME, LifetimePolicy.DELETE_ON_NO_OUTBOUND_LINKS);
 
-        Binding binding = findBinding("amq.direct", TOPIC_NAME);
+        final Binding binding = findBinding("amq.direct", TOPIC_NAME);
         assertNotNull(binding, "Binding is not found");
-        Map<String,Object> arguments = binding.getArguments();
+        final Map<String,Object> arguments = binding.getArguments();
         assertNotNull(arguments, "Unexpected arguments");
         assertEquals(selectorExpression, arguments.get(AMQPFilterTypes.JMS_SELECTOR.toString()),
                 "Unexpected filter on binding");
     }
 
     @Test
-    public void testLinkStealing()
+    void linkStealing()
     {
-        _virtualHost.createChild(Queue.class, Collections.singletonMap(Queue.NAME, QUEUE_NAME));
-        Attach attach = createQueueAttach(true, getTestName(), QUEUE_NAME);
+        _virtualHost.createChild(Queue.class, Map.of(Queue.NAME, QUEUE_NAME));
+        final Attach attach = createQueueAttach(true, getTestName(), QUEUE_NAME);
 
-        AMQPConnection_1_0 connection1 = _connection;
-        Session_1_0 session1 = _session;
+        final AMQPConnection_1_0<?> connection1 = _connection;
+        final Session_1_0 session1 = _session;
         session1.receiveAttach(attach);
 
-        Link_1_0<?,?> link = _virtualHost.getSendingLink(connection1.getRemoteContainerId(), attach.getName());
+        final Link_1_0<?,?> link = _virtualHost.getSendingLink(connection1.getRemoteContainerId(), attach.getName());
         assertNotNull(link, "Link is not created");
         assertAttachSent(connection1, session1, attach);
 
-        AMQPConnection_1_0 connection2 = createAmqpConnection_1_0(connection1.getRemoteContainerId());
-        Session_1_0 session2 = createSession_1_0(connection2, 0);
+        final AMQPConnection_1_0<?> connection2 = createAmqpConnection_1_0(connection1.getRemoteContainerId());
+        final Session_1_0 session2 = createSession_1_0(connection2, 0);
         session2.receiveAttach(attach);
 
         assertDetachSent(connection1, session1, LinkError.STOLEN, 1);
@@ -535,7 +534,7 @@
     }
 
     @Test
-    public void testAttachSourceDynamicWithLifeTimePolicyDeleteOnClose()
+    void attachSourceDynamicWithLifeTimePolicyDeleteOnClose()
     {
         final Attach attach = createReceiverAttach(getTestName());
         final Source source = createDynamicSource(new DeleteOnClose());
@@ -547,7 +546,7 @@
     }
 
     @Test
-    public void testAttachSourceDynamicWithLifeTimePolicyDeleteOnCloseAndExpiryPolicyNever()
+    void attachSourceDynamicWithLifeTimePolicyDeleteOnCloseAndExpiryPolicyNever()
     {
         final Attach attach = createReceiverAttach(getTestName());
         final Source source = createDynamicSource(new DeleteOnClose());
@@ -563,7 +562,7 @@
     {
         final Source source = new Source();
         source.setDynamic(true);
-        source.setDynamicNodeProperties(Collections.singletonMap(Session_1_0.LIFETIME_POLICY, lifetimePolicy));
+        source.setDynamicNodeProperties(Map.of(Session_1_0.LIFETIME_POLICY, lifetimePolicy));
         return source;
     }
 
@@ -574,21 +573,21 @@
         return ((Source) (sentAttach.getSource())).getAddress();
     }
 
-    public void assertQueueDurability(final String queueName, final boolean expectedDurability)
+    void assertQueueDurability(final String queueName, final boolean expectedDurability)
     {
-        final Queue queue = _virtualHost.getChildByName(Queue.class, queueName);
+        final Queue<?> queue = _virtualHost.getChildByName(Queue.class, queueName);
         assertNotNull(queue, "Queue not found");
         assertEquals(queue.isDurable(), expectedDurability, "Unexpected durability");
     }
 
     private void assertFilter(final Attach sentAttach, final String selectorExpression)
     {
-        Source source = (Source)sentAttach.getSource();
-        Map<Symbol, Filter> filter = source.getFilter();
+        final Source source = (Source)sentAttach.getSource();
+        final Map<Symbol, Filter> filter = source.getFilter();
         assertNotNull(filter, "Filter is not set in response");
         assertEquals(1, filter.size(), "Unexpected filter size");
         assertTrue(filter.containsKey(JMS_SELECTOR_FILTER), "Selector is not found");
-        Filter jmsSelectorFilter = filter.get(JMS_SELECTOR_FILTER);
+        final Filter jmsSelectorFilter = filter.get(JMS_SELECTOR_FILTER);
         final boolean condition = jmsSelectorFilter instanceof JMSSelectorFilter;
         assertTrue(condition, "Unexpected selector filter");
         assertEquals(selectorExpression, ((JMSSelectorFilter) jmsSelectorFilter).getValue(), "Unexpected selector");
@@ -596,42 +595,33 @@
 
     private Binding findBinding(final String exchangeName, final String bindingName)
     {
-        Exchange exchange = _virtualHost.findConfiguredObject(Exchange.class, exchangeName);
-        Collection<Binding> bindings = exchange.getBindings();
-        Binding binding = null;
-        for (Binding b: bindings)
-        {
-            if (bindingName.equals(b.getName()))
-            {
-                binding = b;
-                break;
-            }
-        }
-        return binding;
+        final Exchange<?> exchange = _virtualHost.findConfiguredObject(Exchange.class, exchangeName);
+        return exchange.getBindings().stream()
+                .filter(binding -> bindingName.equals(binding.getName()))
+                .findFirst().orElse(null);
     }
 
     private void setSelector(final Attach attach, final String selectorExpression)
     {
-        JMSSelectorFilter selector = new JMSSelectorFilter(selectorExpression);
-        final Map<Symbol, Filter>
-                filter = Collections.singletonMap(Symbol.getSymbol("jms-selector"), selector);
+        final JMSSelectorFilter selector = new JMSSelectorFilter(selectorExpression);
+        final Map<Symbol, Filter> filter = Map.of(Symbol.getSymbol("jms-selector"), selector);
         ((Source)attach.getSource()).setFilter(filter);
     }
 
     private void assertAttachActions(final Queue<?> queue, final Attach receivedAttach)
     {
-        Collection<QueueConsumer<?,?>> consumers = queue.getConsumers();
+        final Collection<QueueConsumer<?,?>> consumers = queue.getConsumers();
         assertEquals(1, (long) consumers.size(), "Unexpected consumers size");
 
-        ArgumentCaptor<FrameBody> frameCapture = ArgumentCaptor.forClass(FrameBody.class);
+        final ArgumentCaptor<FrameBody> frameCapture = ArgumentCaptor.forClass(FrameBody.class);
         verify(_connection).sendFrame(eq(_session.getChannelId()), frameCapture.capture());
-        Attach sentAttach = (Attach) frameCapture.getValue();
+        final Attach sentAttach = (Attach) frameCapture.getValue();
 
         assertEquals(receivedAttach.getName(), sentAttach.getName(), "Unexpected name");
         assertEquals(Role.SENDER, sentAttach.getRole(), "Unexpected role");
 
-        Source receivedSource = (Source) receivedAttach.getSource();
-        Source sentSource = (Source) sentAttach.getSource();
+        final Source receivedSource = (Source) receivedAttach.getSource();
+        final Source sentSource = (Source) sentAttach.getSource();
         assertEquals(receivedSource.getAddress(), sentSource.getAddress(), "Unexpected source address");
         assertArrayEquals(receivedSource.getCapabilities(), sentSource.getCapabilities(),
                 "Unexpected source capabilities");
@@ -640,8 +630,8 @@
                 "Unexpected source expiry policy");
         assertEquals(receivedSource.getDynamic(), sentSource.getDynamic(), "Unexpected source dynamic flag");
 
-        Target receivedTarget = (Target) receivedAttach.getTarget();
-        Target sentTarget = (Target) sentAttach.getTarget();
+        final Target receivedTarget = (Target) receivedAttach.getTarget();
+        final Target sentTarget = (Target) sentAttach.getTarget();
         assertEquals(receivedTarget.getAddress(), sentTarget.getAddress(), "Unexpected target address");
         assertArrayEquals(receivedTarget.getCapabilities(), sentTarget.getCapabilities(),
                 "Unexpected target capabilities");
@@ -659,42 +649,42 @@
                                   final ErrorCondition expectedError,
                                   final int invocationOffset)
     {
-        ArgumentCaptor<FrameBody> frameCapture = ArgumentCaptor.forClass(FrameBody.class);
+        final ArgumentCaptor<FrameBody> frameCapture = ArgumentCaptor.forClass(FrameBody.class);
         verify(connection, times(invocationOffset + 1)).sendFrame(eq(session.getChannelId()), frameCapture.capture());
-        List<FrameBody> sentFrames = frameCapture.getAllValues();
+        final List<FrameBody> sentFrames = frameCapture.getAllValues();
 
         final boolean condition = sentFrames.get(invocationOffset) instanceof Detach;
         assertTrue(condition, "unexpected Frame sent");
-        Detach sentDetach = (Detach) sentFrames.get(invocationOffset);
+        final Detach sentDetach = (Detach) sentFrames.get(invocationOffset);
         assertTrue(sentDetach.getClosed(), "Unexpected closed state");
         assertEquals(expectedError, sentDetach.getError().getCondition(), "Closed with unexpected error condition");
     }
 
-    private void assertAttachSent(final AMQPConnection_1_0 connection,
+    private void assertAttachSent(final AMQPConnection_1_0<?> connection,
                                   final Session_1_0 session,
                                   final Attach receivedAttach)
     {
         assertAttachSent(connection, session, receivedAttach, 0);
     }
 
-    private void assertAttachSent(final AMQPConnection_1_0 connection,
+    private void assertAttachSent(final AMQPConnection_1_0<?> connection,
                                   final Session_1_0 session,
                                   final Attach receivedAttach,
                                   final int invocationOffset)
     {
-        Attach sentAttach = captureAttach(connection, session, invocationOffset);
+        final Attach sentAttach = captureAttach(connection, session, invocationOffset);
 
         assertEquals(receivedAttach.getName(), sentAttach.getName(), "Unexpected name");
         assertEquals(Role.SENDER, sentAttach.getRole(), "Unexpected role");
     }
 
-    private Attach captureAttach(final AMQPConnection_1_0 connection,
+    private Attach captureAttach(final AMQPConnection_1_0<?> connection,
                                  final Session_1_0 session,
                                  final int invocationOffset)
     {
-        ArgumentCaptor<FrameBody> frameCapture = ArgumentCaptor.forClass(FrameBody.class);
-        verify(connection, times(invocationOffset + 1)).sendFrame(eq(session.getChannelId()),
-                                                                  frameCapture.capture());
+        final ArgumentCaptor<FrameBody> frameCapture = ArgumentCaptor.forClass(FrameBody.class);
+        verify(connection, times(invocationOffset + 1))
+                .sendFrame(eq(session.getChannelId()), frameCapture.capture());
         return (Attach) frameCapture.getAllValues().get(invocationOffset);
     }
 
@@ -702,37 +692,40 @@
     {
         final Collection<Queue> queues = _virtualHost.getChildren(Queue.class);
         assertEquals(1, (long) queues.size(), "Unexpected number of queues after attach");
-        Queue<?> queue = queues.iterator().next();
+        final Queue<?> queue = queues.iterator().next();
         assertEquals(expectedLifetimePolicy, queue.getLifetimePolicy(), "Unexpected queue durability");
 
-        Collection<PublishingLink> queuePublishingLinks = queue.getPublishingLinks();
+        final Collection<PublishingLink> queuePublishingLinks = queue.getPublishingLinks();
         assertEquals(1, (long) queuePublishingLinks.size(), "Unexpected number of publishing links");
         assertEquals(publishingLinkName, queuePublishingLinks.iterator().next().getName(), "Unexpected link name");
 
-        Exchange<?> exchange = _virtualHost.getChildByName(Exchange.class, "amq.direct");
+        final Exchange<?> exchange = _virtualHost.getChildByName(Exchange.class, "amq.direct");
         assertTrue(exchange.hasBinding(publishingLinkName, queue), "Binding should exist");
     }
 
-    private void assertAttachFailed(final AMQPConnection_1_0 connection, final Session_1_0 session, final Attach attach, int invocationOffset)
+    private void assertAttachFailed(final AMQPConnection_1_0<?> connection,
+                                    final Session_1_0 session,
+                                    final Attach attach,
+                                    int invocationOffset)
     {
-        ArgumentCaptor<FrameBody> frameCapture = ArgumentCaptor.forClass(FrameBody.class);
+        final ArgumentCaptor<FrameBody> frameCapture = ArgumentCaptor.forClass(FrameBody.class);
         verify(connection, times(invocationOffset + 2)).sendFrame(eq(session.getChannelId()), frameCapture.capture());
-        List<FrameBody> sentFrames = frameCapture.getAllValues();
+        final List<FrameBody> sentFrames = frameCapture.getAllValues();
 
         final boolean condition1 = sentFrames.get(invocationOffset) instanceof Attach;
         assertTrue(condition1, "unexpected Frame sent");
-        Attach sentAttach = (Attach) sentFrames.get(invocationOffset);
+        final Attach sentAttach = (Attach) sentFrames.get(invocationOffset);
         assertEquals(attach.getName(), sentAttach.getName(), "Unexpected name");
         assertEquals(Role.SENDER, sentAttach.getRole(), "Unexpected role");
         assertNull(sentAttach.getSource(), "Unexpected source");
 
         final boolean condition = sentFrames.get(invocationOffset + 1) instanceof Detach;
         assertTrue(condition, "unexpected Frame sent");
-        Detach sentDetach = (Detach) sentFrames.get(invocationOffset + 1);
+        final Detach sentDetach = (Detach) sentFrames.get(invocationOffset + 1);
         assertTrue(sentDetach.getClosed(), "Unexpected closed state");
     }
 
-    private void assertAttachFailed(final AMQPConnection_1_0 connection, final Session_1_0 session, final Attach attach)
+    private void assertAttachFailed(final AMQPConnection_1_0<?> connection, final Session_1_0 session, final Attach attach)
     {
         assertAttachFailed(connection, session, attach, 0);
     }
@@ -767,10 +760,10 @@
                                 final boolean isGlobal,
                                 final boolean isShared)
     {
-        Attach attach = createReceiverAttach(linkName);
-        Source source = new Source();
+        final Attach attach = createReceiverAttach(linkName);
+        final Source source = new Source();
 
-        List<Symbol> capabilities = new ArrayList<>();
+        final List<Symbol> capabilities = new ArrayList<>();
         if (isGlobal)
         {
             capabilities.add(Symbol.getSymbol("global"));
@@ -781,8 +774,7 @@
         }
         capabilities.add(destinationTypeCapability);
 
-
-        source.setCapabilities(capabilities.toArray(new Symbol[capabilities.size()]));
+        source.setCapabilities(capabilities.toArray(new Symbol[0]));
         if (durable)
         {
             source.setDurable(TerminusDurability.CONFIGURATION);
@@ -798,10 +790,10 @@
         return attach;
     }
 
-    private Attach createReceiverAttach(String linkName)
+    private Attach createReceiverAttach(final String linkName)
     {
         final Attach attach = new Attach();
-        Target target = new Target();
+        final Target target = new Target();
         attach.setTarget(target);
         attach.setHandle(new UnsignedInteger(_handle++));
         attach.setIncompleteUnsettled(false);
@@ -810,16 +802,15 @@
         return attach;
     }
 
-    private AMQPConnection_1_0 createAmqpConnection_1_0()
+    private AMQPConnection_1_0<?> createAmqpConnection_1_0()
     {
         return createAmqpConnection_1_0(null);
     }
 
-    private AMQPConnection_1_0 createAmqpConnection_1_0(String containerId)
+    private AMQPConnection_1_0<?> createAmqpConnection_1_0(final String containerId)
     {
-        AMQPConnection_1_0 connection = BrokerTestHelper.mockAsSystemPrincipalSource(AMQPConnection_1_0.class);
-        Subject subject =
-                new Subject(true, Collections.emptySet(), Collections.emptySet(), Collections.emptySet());
+        final AMQPConnection_1_0<?> connection = BrokerTestHelper.mockAsSystemPrincipalSource(AMQPConnection_1_0.class);
+        final Subject subject = new Subject(true, Set.of(), Set.of(), Set.of());
         when(connection.getSubject()).thenReturn(subject);
         when(connection.getAddressSpace()).thenReturn(_virtualHost);
         when(connection.getEventLogger()).thenReturn(mock(EventLogger.class));
@@ -838,7 +829,7 @@
             runnableCaptor.getValue().run();
             return Futures.immediateFuture(null);
         });
-        AggregateTicker mockTicker = mock(AggregateTicker.class);
+        final AggregateTicker mockTicker = mock(AggregateTicker.class);
         when(connection.getAggregateTicker()).thenReturn(mockTicker);
         if (containerId != null)
         {
@@ -852,9 +843,9 @@
         return connection;
     }
 
-    private Session_1_0 createSession_1_0(final AMQPConnection_1_0 connection, int channelId)
+    private Session_1_0 createSession_1_0(final AMQPConnection_1_0<?> connection, int channelId)
     {
-        Begin begin = mock(Begin.class);
+        final Begin begin = mock(Begin.class);
         when(begin.getNextOutgoingId()).thenReturn(new UnsignedInteger(channelId));
         return new Session_1_0(connection, begin, channelId, channelId, 2048);
     }
diff --git a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/TestLinkStoreFactory.java b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/TestLinkStoreFactory.java
index fa05331..849e115 100644
--- a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/TestLinkStoreFactory.java
+++ b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/TestLinkStoreFactory.java
@@ -21,7 +21,7 @@
 package org.apache.qpid.server.protocol.v1_0;
 
 import java.util.Collection;
-import java.util.Collections;
+import java.util.List;
 
 import org.apache.qpid.server.model.NamedAddressSpace;
 import org.apache.qpid.server.plugin.PluggableService;
@@ -52,7 +52,7 @@
             @Override
             public Collection<LinkDefinition<Source, Target>> openAndLoad(final LinkStoreUpdater updater) throws StoreException
             {
-                return Collections.emptyList();
+                return List.of();
             }
 
             @Override
diff --git a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/codec/StringTypeConstructorTest.java b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/codec/StringTypeConstructorTest.java
index 7039889..e3982a6 100644
--- a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/codec/StringTypeConstructorTest.java
+++ b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/codec/StringTypeConstructorTest.java
@@ -32,19 +32,19 @@
 
 import org.apache.qpid.server.bytebuffer.QpidByteBuffer;
 
-public class StringTypeConstructorTest
+class StringTypeConstructorTest
 {
     @Test
-    public void construct() throws Exception
+    void construct() throws Exception
     {
-        StringTypeConstructor constructor = StringTypeConstructor.getInstance(1);
-        Cache<ByteBuffer, String> original = StringTypeConstructor.getCache();
-        Cache<ByteBuffer, String> cache = CacheBuilder.newBuilder().maximumSize(2).build();
+        final StringTypeConstructor constructor = StringTypeConstructor.getInstance(1);
+        final Cache<ByteBuffer, String> original = StringTypeConstructor.getCache();
+        final Cache<ByteBuffer, String> cache = CacheBuilder.newBuilder().maximumSize(2).build();
         StringTypeConstructor.setCache(cache);
         try
         {
-            String string1 = constructor.construct(QpidByteBuffer.wrap(new byte[]{4, 't', 'e', 's', 't'}), null);
-            String string2 = constructor.construct(QpidByteBuffer.wrap(new byte[]{4, 't', 'e', 's', 't'}), null);
+            final String string1 = constructor.construct(QpidByteBuffer.wrap(new byte[]{4, 't', 'e', 's', 't'}), null);
+            final String string2 = constructor.construct(QpidByteBuffer.wrap(new byte[]{4, 't', 'e', 's', 't'}), null);
             assertEquals(string1, string2);
             assertSame(string1, string2);
         }
diff --git a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/codec/ValueHandlerTest.java b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/codec/ValueHandlerTest.java
index 1260a41..e0aa79e 100644
--- a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/codec/ValueHandlerTest.java
+++ b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/codec/ValueHandlerTest.java
@@ -21,7 +21,7 @@
 package org.apache.qpid.server.protocol.v1_0.codec;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.fail;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
@@ -32,9 +32,9 @@
 import org.apache.qpid.server.protocol.v1_0.type.transport.AmqpError;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class ValueHandlerTest extends UnitTestBase
+class ValueHandlerTest extends UnitTestBase
 {
-    private final byte[] FORMAT_CODES = {
+    private static final byte[] FORMAT_CODES = {
             0x00,
             0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56,
             0x60, 0x61,
@@ -50,25 +50,25 @@
     };
 
     private static final AMQPDescribedTypeRegistry TYPE_REGISTRY = AMQPDescribedTypeRegistry.newInstance()
-                                                                                            .registerTransportLayer()
-                                                                                            .registerMessagingLayer()
-                                                                                            .registerTransactionLayer()
-                                                                                            .registerSecurityLayer();
+            .registerTransportLayer()
+            .registerMessagingLayer()
+            .registerTransactionLayer()
+            .registerSecurityLayer();
 
     private ValueHandler _valueHandle;
     private ValueHandler _sectionValueHandler;
 
     @BeforeAll
-    public void setUp() throws Exception
+    void setUp()
     {
         _valueHandle = new ValueHandler(TYPE_REGISTRY);
         _sectionValueHandler = new ValueHandler(TYPE_REGISTRY.getSectionDecoderRegistry());
     }
 
     @Test
-    public void testIncompleteValueParsingFormatCodeOnly()
+    void incompleteValueParsingFormatCodeOnly()
     {
-        for (byte b : FORMAT_CODES)
+        for (final byte b : FORMAT_CODES)
         {
             byte[] in = {b};
             performTest(b, in);
@@ -76,100 +76,99 @@
     }
 
     @Test
-    public void testIncompleteValueParsingVariableOneFormatCodeOnlyAndSize()
+    void incompleteValueParsingVariableOneFormatCodeOnlyAndSize()
     {
-        byte[] variableOne = {(byte) 0xA0, (byte) 0xA1, (byte) 0xA3};
-        for (byte b : variableOne)
+        final byte[] variableOne = {(byte) 0xA0, (byte) 0xA1, (byte) 0xA3};
+        for (final byte b : variableOne)
         {
-            byte[] in = {b, (byte) 1};
+            final byte[] in = {b, (byte) 1};
             performTest(b, in);
         }
     }
 
     @Test
-    public void testIncompleteValueParsingVariableFour()
+    void incompleteValueParsingVariableFour()
     {
-        byte[] variableFour = {(byte) 0xB0, (byte) 0xB1, (byte) 0xB3};
-        for (byte b : variableFour)
+        final byte[] variableFour = {(byte) 0xB0, (byte) 0xB1, (byte) 0xB3};
+        for (final byte b : variableFour)
         {
-            byte[] in = {b, (byte) 0, (byte) 0, (byte) 0, (byte) 2};
+            final byte[] in = {b, (byte) 0, (byte) 0, (byte) 0, (byte) 2};
             performTest(b, in);
         }
     }
 
     @Test
-    public void testIncompleteValueParsingCompoundOneOrArrayOne()
+    void incompleteValueParsingCompoundOneOrArrayOne()
     {
-        byte[] compoundOne = {(byte) 0xC0, (byte) 0xC1, (byte) 0xE0};
-        for (byte b : compoundOne)
+        final byte[] compoundOne = {(byte) 0xC0, (byte) 0xC1, (byte) 0xE0};
+        for (final byte b : compoundOne)
         {
-            byte[] in = {b, (byte) 1};
+            final byte[] in = {b, (byte) 1};
             performTest(b, in);
         }
     }
 
     @Test
-    public void testIncompleteValueParsingCompoundFourOrArrayFour()
+    void incompleteValueParsingCompoundFourOrArrayFour()
     {
-        byte[] compoundFour = {(byte) 0xD0, (byte) 0xD1, (byte) 0xF0};
-        for (byte b : compoundFour)
+        final byte[] compoundFour = {(byte) 0xD0, (byte) 0xD1, (byte) 0xF0};
+        for (final byte b : compoundFour)
         {
-            byte[] in = {b, (byte) 0, (byte) 0, (byte) 0, (byte) 1};
-            performTest(b, in);
-        }
-    }
-
-
-    @Test
-    public void testIncompleteValueParsingCompoundOneWhenOnlySizeAndCountSpecified()
-    {
-        byte[] compoundOne = {(byte) 0xC0, (byte) 0xC1, (byte) 0xE0};
-        for (byte b : compoundOne)
-        {
-            byte[] in = {b, (byte) 2, (byte) 1};
+            final byte[] in = {b, (byte) 0, (byte) 0, (byte) 0, (byte) 1};
             performTest(b, in);
         }
     }
 
     @Test
-    public void testIncompleteValueParsingCompoundFourWhenOnlySizeAndCountSpecified()
+    void incompleteValueParsingCompoundOneWhenOnlySizeAndCountSpecified()
     {
-        byte[] compoundFour = {(byte) 0xD0, (byte) 0xD1, (byte) 0xF0};
-        for (byte b : compoundFour)
+        final byte[] compoundOne = {(byte) 0xC0, (byte) 0xC1, (byte) 0xE0};
+        for (final byte b : compoundOne)
         {
-            byte[] in = {b, (byte) 0, (byte) 0, (byte) 0, (byte) 2, (byte) 0, (byte) 0, (byte) 0, (byte) 1};
+            final byte[] in = {b, (byte) 2, (byte) 1};
             performTest(b, in);
         }
     }
 
     @Test
-    public void testIncompleteValueParsingArrayOneElementConstructor()
+    void incompleteValueParsingCompoundFourWhenOnlySizeAndCountSpecified()
     {
-        byte[] in = {(byte) 0xE0, (byte) 3, (byte) 1, 0x50};
+        final byte[] compoundFour = {(byte) 0xD0, (byte) 0xD1, (byte) 0xF0};
+        for (final byte b : compoundFour)
+        {
+            final byte[] in = {b, (byte) 0, (byte) 0, (byte) 0, (byte) 2, (byte) 0, (byte) 0, (byte) 0, (byte) 1};
+            performTest(b, in);
+        }
+    }
+
+    @Test
+    void incompleteValueParsingArrayOneElementConstructor()
+    {
+        final byte[] in = {(byte) 0xE0, (byte) 3, (byte) 1, 0x50};
         performTest((byte) 0xE0, in);
     }
 
     @Test
-    public void testIncompleteValueParsingArrayOneElementConstructorWhenSizeIsWrong()
+    void incompleteValueParsingArrayOneElementConstructorWhenSizeIsWrong()
     {
-        byte[] in = {(byte) 0xE0, (byte) 2, (byte) 1, 0x50, (byte) 1};
+        final byte[] in = {(byte) 0xE0, (byte) 2, (byte) 1, 0x50, (byte) 1};
         performTest((byte) 0xE0, in);
     }
 
     @Test
-    public void testIncompleteValueParsingArrayFourElementConstructor()
+    void incompleteValueParsingArrayFourElementConstructor()
     {
-        byte[] in = {(byte) 0xF0, (byte) 0, (byte) 0, (byte) 0, (byte) 2, (byte) 0, (byte) 0, (byte) 0, (byte) 1, 0x50};
+        final byte[] in = {(byte) 0xF0, (byte) 0, (byte) 0, (byte) 0, (byte) 2, (byte) 0, (byte) 0, (byte) 0, (byte) 1, 0x50};
         performTest((byte) 0xF0, in);
     }
 
     @Test
-    public void testIncompleteSection()
+    void incompleteSection()
     {
-        byte[] in = { 0x00, 0x53, 0x75, (byte) 0xA0, 0x01, 0x00 };
+        final byte[] in = { 0x00, 0x53, 0x75, (byte) 0xA0, 0x01, 0x00 };
         for (int i = in.length - 1; i > 1; --i)
         {
-            byte[] newArray = new byte[i];
+            final byte[] newArray = new byte[i];
             System.arraycopy(in, 0, newArray, 0, i);
             performSectionTest((byte) 0x00, newArray);
         }
@@ -185,24 +184,14 @@
         performTest(type, encodedBytes, _valueHandle);
     }
 
-    private void performTest(final byte type, final byte[] encodedBytes, ValueHandler valueHandler)
+    private void performTest(final byte type, final byte[] encodedBytes, final ValueHandler valueHandler)
     {
-        QpidByteBuffer qbb = QpidByteBuffer.wrap(encodedBytes);
+        final QpidByteBuffer qbb = QpidByteBuffer.wrap(encodedBytes);
 
-        try
-        {
-            valueHandler.parse(qbb);
-            fail(String.format("AmqpErrorException is expected for %#02x", type));
-        }
-        catch (AmqpErrorException e)
-        {
-            assertEquals(AmqpError.DECODE_ERROR, e.getError().getCondition(),
-                    String.format("Unexpected error code for %#02x", type));
-
-        }
-        catch (Exception e)
-        {
-            fail(String.format("Unexpected exception for %#02x: %s", type, e));
-        }
+        final AmqpErrorException thrown =  assertThrows(AmqpErrorException.class,
+                () -> valueHandler.parse(qbb),
+                String.format("AmqpErrorException is expected for %#02x", type));
+        assertEquals(AmqpError.DECODE_ERROR, thrown.getError().getCondition(),
+                String.format("Unexpected error code for %#02x", type));
     }
 }
diff --git a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/delivery/DeliveryRegistryImplTest.java b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/delivery/DeliveryRegistryImplTest.java
index 7c639e6..d88f59f 100644
--- a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/delivery/DeliveryRegistryImplTest.java
+++ b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/delivery/DeliveryRegistryImplTest.java
@@ -34,24 +34,25 @@
 import org.apache.qpid.server.protocol.v1_0.type.UnsignedInteger;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class DeliveryRegistryImplTest extends UnitTestBase
+class DeliveryRegistryImplTest extends UnitTestBase
 {
     private static final UnsignedInteger DELIVERY_ID = UnsignedInteger.ZERO;
     private static final UnsignedInteger DELIVERY_ID_2 = UnsignedInteger.ONE;
     private static final Binary DELIVERY_TAG = new Binary(new byte[]{(byte) 32, (byte) 33});
     private static final Binary DELIVERY_TAG_2 = new Binary(new byte[]{(byte) 32});
 
-    private DeliveryRegistryImpl _registry;
     private final UnsettledDelivery _unsettledDelivery = new UnsettledDelivery(DELIVERY_TAG, mock(LinkEndpoint.class));
 
+    private DeliveryRegistryImpl _registry;
+
     @BeforeEach
-    public void setUp()
+    void setUp()
     {
         _registry = new DeliveryRegistryImpl();
     }
 
     @Test
-    public void addDelivery()
+    void addDelivery()
     {
         assertThat(_registry.size(), is(equalTo(0)));
 
@@ -61,7 +62,7 @@
     }
 
     @Test
-    public void removeDelivery()
+    void removeDelivery()
     {
         _registry.addDelivery(DELIVERY_ID, _unsettledDelivery);
         assertThat(_registry.size(), is(equalTo(1)));
@@ -71,7 +72,7 @@
     }
 
     @Test
-    public void getDelivery()
+    void getDelivery()
     {
         _registry.addDelivery(DELIVERY_ID, _unsettledDelivery);
 
@@ -82,7 +83,7 @@
     }
 
     @Test
-    public void removeDeliveriesForLinkEndpoint()
+    void removeDeliveriesForLinkEndpoint()
     {
         _registry.addDelivery(DELIVERY_ID, _unsettledDelivery);
         _registry.addDelivery(DELIVERY_ID_2, new UnsettledDelivery(DELIVERY_TAG_2, _unsettledDelivery.getLinkEndpoint()));
@@ -96,7 +97,7 @@
     }
 
     @Test
-    public void getDeliveryId()
+    void getDeliveryId()
     {
         _registry.addDelivery(DELIVERY_ID, _unsettledDelivery);
         _registry.addDelivery(DELIVERY_ID_2, new UnsettledDelivery(DELIVERY_TAG, mock(LinkEndpoint.class)));
@@ -107,7 +108,7 @@
     }
 
     @Test
-    public void size()
+    void size()
     {
         assertThat(_registry.size(), is(equalTo(0)));
 
diff --git a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/delivery/UnsettledDeliveryTest.java b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/delivery/UnsettledDeliveryTest.java
index d604b5a..e914833 100644
--- a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/delivery/UnsettledDeliveryTest.java
+++ b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/delivery/UnsettledDeliveryTest.java
@@ -34,15 +34,16 @@
 import org.apache.qpid.server.protocol.v1_0.type.Binary;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class UnsettledDeliveryTest extends UnitTestBase
+class UnsettledDeliveryTest extends UnitTestBase
 {
     private static final byte[] DATA = new byte[]{(byte) 32, (byte) 33, (byte) 34};
+
     private Binary _deliveryTag;
     private LinkEndpoint<?, ?> _linkEndpoint;
     private UnsettledDelivery _unsettledDelivery;
 
     @BeforeAll
-    public void setUp()
+    void setUp()
     {
         _deliveryTag = new Binary(DATA);
         _linkEndpoint = mock(LinkEndpoint.class);
@@ -50,47 +51,47 @@
     }
 
     @Test
-    public void testGetDeliveryTag()
+    void getDeliveryTag()
     {
         assertThat(_unsettledDelivery.getDeliveryTag(), is(equalTo(_deliveryTag)));
     }
 
     @Test
-    public void testGetLinkEndpoint()
+    void getLinkEndpoint()
     {
         assertThat(_unsettledDelivery.getLinkEndpoint(), is(equalTo(_linkEndpoint)));
     }
 
     @Test
-    public void testEqualsToNewUnsettledDeliveryWithTheSameFields()
+    void equalsToNewUnsettledDeliveryWithTheSameFields()
     {
         assertThat(_unsettledDelivery.equals(new UnsettledDelivery(_deliveryTag, _linkEndpoint)), is(equalTo(true)));
     }
 
     @Test
-    public void testEqualsToNewUnsettledDeliveryWithEqualsFields()
+    void equalsToNewUnsettledDeliveryWithEqualsFields()
     {
         assertThat(_unsettledDelivery.equals(new UnsettledDelivery(new Binary(DATA), _linkEndpoint)),
-                   is(equalTo(true)));
+                is(equalTo(true)));
     }
 
     @Test
-    public void testNotEqualsWhenDeliveryTagIsDifferent()
+    void notEqualsWhenDeliveryTagIsDifferent()
     {
         assertThat(_unsettledDelivery.equals(new UnsettledDelivery(new Binary(new byte[]{(byte) 32, (byte) 33}),
-                                                                   _linkEndpoint)), is(equalTo(false)));
+                _linkEndpoint)), is(equalTo(false)));
     }
 
     @Test
-    public void testNotEqualsWhenLinkEndpointIsDifferent()
+    void notEqualsWhenLinkEndpointIsDifferent()
     {
         final LinkEndpoint<?, ?> linkEndpoint = mock(LinkEndpoint.class);
         assertThat(_unsettledDelivery.equals(new UnsettledDelivery(new Binary(new byte[]{(byte) 32, (byte) 33}),
-                                                                   linkEndpoint)), is(equalTo(false)));
+                linkEndpoint)), is(equalTo(false)));
     }
 
     @Test
-    public void testHashCode()
+    void hashCodes()
     {
         int expected = Objects.hash(_deliveryTag, _linkEndpoint);
         assertThat(_unsettledDelivery.hashCode(), is(equalTo(expected)));
diff --git a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/framing/FrameHandlerTest.java b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/framing/FrameHandlerTest.java
index 160e368..0f4aa8b 100644
--- a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/framing/FrameHandlerTest.java
+++ b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/framing/FrameHandlerTest.java
@@ -40,25 +40,26 @@
 import org.apache.qpid.server.protocol.v1_0.type.transport.Error;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class FrameHandlerTest extends UnitTestBase
+class FrameHandlerTest extends UnitTestBase
 {
     private static final int MAX_FRAME_SIZE = 4096;
+
     private ValueHandler _valueHandler;
 
     @BeforeAll
-    public void setUp() throws Exception
+    void setUp()
     {
         _valueHandler = new ValueHandler(AMQPDescribedTypeRegistry.newInstance());
     }
 
     @Test
-    public void testSaslHeartbeat()
+    void saslHeartbeat()
     {
-        ConnectionHandler connectionHandler = mock(ConnectionHandler.class);
+        final ConnectionHandler connectionHandler = mock(ConnectionHandler.class);
         when(connectionHandler.getMaxFrameSize()).thenReturn(MAX_FRAME_SIZE);
-        FrameHandler handler = new  FrameHandler(_valueHandler, connectionHandler, true);
+        final FrameHandler handler = new  FrameHandler(_valueHandler, connectionHandler, true);
 
-        QpidByteBuffer body = QpidByteBuffer.allocate(false, 8);
+        final QpidByteBuffer body = QpidByteBuffer.allocate(false, 8);
         body.putInt(8);    // size
         body.put((byte)2); // DOFF
         body.put((byte)1); // AMQP Frame Type
@@ -67,23 +68,23 @@
 
         handler.parse(body);
 
-        ArgumentCaptor<Error> errorCaptor = ArgumentCaptor.forClass(Error.class);
+        final ArgumentCaptor<Error> errorCaptor = ArgumentCaptor.forClass(Error.class);
         verify(connectionHandler).handleError(errorCaptor.capture());
 
-        Error error = errorCaptor.getValue();
+        final Error error = errorCaptor.getValue();
         assertNotNull(error);
         assertEquals(ConnectionError.FRAMING_ERROR, error.getCondition());
         assertEquals("Empty (heartbeat) frames are not permitted during SASL negotiation", error.getDescription());
     }
 
     @Test
-    public void testOversizedFrame()
+    void oversizedFrame()
     {
-        ConnectionHandler connectionHandler = mock(ConnectionHandler.class);
+        final ConnectionHandler connectionHandler = mock(ConnectionHandler.class);
         when(connectionHandler.getMaxFrameSize()).thenReturn(MAX_FRAME_SIZE);
-        FrameHandler handler = new FrameHandler(_valueHandler, connectionHandler, true);
+        final FrameHandler handler = new FrameHandler(_valueHandler, connectionHandler, true);
 
-        QpidByteBuffer body = QpidByteBuffer.allocate(false, MAX_FRAME_SIZE + 8);
+        final QpidByteBuffer body = QpidByteBuffer.allocate(false, MAX_FRAME_SIZE + 8);
         body.putInt(body.capacity()); // size
         body.put((byte) 2); // DOFF
         body.put((byte) 1); // AMQP Frame Type
@@ -93,10 +94,10 @@
 
         handler.parse(body);
 
-        ArgumentCaptor<Error> errorCaptor = ArgumentCaptor.forClass(Error.class);
+        final ArgumentCaptor<Error> errorCaptor = ArgumentCaptor.forClass(Error.class);
         verify(connectionHandler).handleError(errorCaptor.capture());
 
-        Error error = errorCaptor.getValue();
+        final Error error = errorCaptor.getValue();
         assertNotNull(error);
         assertEquals(ConnectionError.FRAMING_ERROR, error.getCondition());
         assertEquals(String.format("specified frame size %s larger than maximum frame header size %s", body.capacity(),
diff --git a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/store/LinkStoreTestCase.java b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/store/LinkStoreTestCase.java
index 04e9a9f..ceb2212 100644
--- a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/store/LinkStoreTestCase.java
+++ b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/store/LinkStoreTestCase.java
@@ -21,11 +21,11 @@
 package org.apache.qpid.server.protocol.v1_0.store;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
-import static org.junit.jupiter.api.Assertions.fail;
 
 import java.util.Collection;
-import java.util.Collections;
+import java.util.Map;
 
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
@@ -71,15 +71,13 @@
         _source.setDurable(TerminusDurability.UNSETTLED_STATE);
         _source.setDynamic(Boolean.TRUE);
         _source.setExpiryPolicy(TerminusExpiryPolicy.CONNECTION_CLOSE);
-        _source.setFilter(Collections.singletonMap(Symbol.valueOf("foo"), NoLocalFilter.INSTANCE));
+        _source.setFilter(Map.of(Symbol.valueOf("foo"), NoLocalFilter.INSTANCE));
         _source.setOutcomes(new Accepted().getSymbol());
-        _source.setDynamicNodeProperties(Collections.singletonMap(Symbol.valueOf("dynamicProperty"),
-                                                                  "dynamicPropertyValue"));
+        _source.setDynamicNodeProperties(Map.of(Symbol.valueOf("dynamicProperty"), "dynamicPropertyValue"));
         _source.setTimeout(new UnsignedInteger(1));
 
         _target.setTimeout(new UnsignedInteger(2));
-        _target.setDynamicNodeProperties(Collections.singletonMap(Symbol.valueOf("targetDynamicProperty"),
-                                                                  "targetDynamicPropertyValue"));
+        _target.setDynamicNodeProperties(Map.of(Symbol.valueOf("targetDynamicProperty"), "targetDynamicPropertyValue"));
         _target.setDynamic(Boolean.TRUE);
         _target.setExpiryPolicy(TerminusExpiryPolicy.LINK_DETACH);
         _target.setAddress("bar");
@@ -94,22 +92,16 @@
     }
 
     @Test
-    public void testOpenAndLoad()
+    public void openAndLoad()
     {
         Collection<LinkDefinition<Source, Target>> links = _linkStore.openAndLoad(new LinkStoreUpdaterImpl());
         assertTrue(links.isEmpty(), "Unexpected links");
 
-        try
-        {
-            _linkStore.openAndLoad(new LinkStoreUpdaterImpl());
-            fail("Repeated open of already opened store should fail");
-        }
-        catch (StoreException e)
-        {
-            // pass
-        }
+        assertThrows(StoreException.class,
+                () -> _linkStore.openAndLoad(new LinkStoreUpdaterImpl()),
+                "Repeated open of already opened store should fail");
 
-        LinkDefinition<Source, Target> linkDefinition = createLinkDefinition("1", "test");
+        final LinkDefinition<Source, Target> linkDefinition = createLinkDefinition("1", "test");
         _linkStore.saveLink(linkDefinition);
         _linkStore.close();
 
@@ -117,48 +109,35 @@
         assertEquals(1, links.size(), "Unexpected link number");
     }
 
-
     @Test
-    public void testClose() throws Exception
+    public void close()
     {
         _linkStore.openAndLoad(new LinkStoreUpdaterImpl());
-
         _linkStore.close();
-        try
+
+        assertThrows(StoreException.class, () ->
         {
             LinkDefinition<Source, Target> linkDefinition = createLinkDefinition("1", "test");
             _linkStore.saveLink(linkDefinition);
-            fail("Saving link with close store should fail");
-        }
-        catch (StoreException e)
-        {
-            // pass
-        }
+        }, "Saving link with close store should fail");
     }
 
     @Test
-    public void testSaveLink()
+    public void saveLink()
     {
-
-        LinkDefinition<Source, Target> linkDefinition = createLinkDefinition("1", "test");
+        final LinkDefinition<Source, Target> linkDefinition = createLinkDefinition("1", "test");
         _linkStore.openAndLoad(new LinkStoreUpdaterImpl());
         _linkStore.saveLink(linkDefinition);
         _linkStore.close();
 
-        try
-        {
-            _linkStore.saveLink(createLinkDefinition("2", "test2"));
-            fail("Save on unopened database should fail");
-        }
-        catch (StoreException e)
-        {
-            // pass
-        }
+        assertThrows(StoreException.class,
+                () -> _linkStore.saveLink(createLinkDefinition("2", "test2")),
+                "Save on unopened database should fail");
 
-        Collection<LinkDefinition<Source, Target>> links = _linkStore.openAndLoad(new LinkStoreUpdaterImpl());
+        final Collection<LinkDefinition<Source, Target>> links = _linkStore.openAndLoad(new LinkStoreUpdaterImpl());
         assertEquals(1, links.size(), "Unexpected link number");
 
-        LinkDefinition<Source, Target> recoveredLink = links.iterator().next();
+        final LinkDefinition<Source, Target> recoveredLink = links.iterator().next();
 
         assertEquals(linkDefinition.getName(), recoveredLink.getName(), "Unexpected link name");
         assertEquals(linkDefinition.getRemoteContainerId(), recoveredLink.getRemoteContainerId(),
@@ -169,33 +148,27 @@
     }
 
     @Test
-    public void testDeleteLink()
+    public void deleteLink()
     {
         _linkStore.openAndLoad(new LinkStoreUpdaterImpl());
 
-        LinkDefinition<Source, Target> linkDefinition = createLinkDefinition("1", "test");
+        final LinkDefinition<Source, Target> linkDefinition = createLinkDefinition("1", "test");
         _linkStore.saveLink(linkDefinition);
 
-        LinkDefinition<Source, Target> linkDefinition2 = createLinkDefinition("2", "test2");
+        final LinkDefinition<Source, Target> linkDefinition2 = createLinkDefinition("2", "test2");
         _linkStore.saveLink(linkDefinition2);
 
         _linkStore.deleteLink(linkDefinition2);
         _linkStore.close();
 
-        try
-        {
-            _linkStore.deleteLink(linkDefinition);
-            fail("Delete on unopened database should fail");
-        }
-        catch (StoreException e)
-        {
-            // pass
-        }
+        assertThrows(StoreException.class,
+                () -> _linkStore.deleteLink(linkDefinition),
+                "Delete on unopened database should fail");
 
-        Collection<LinkDefinition<Source, Target>> links = _linkStore.openAndLoad(new LinkStoreUpdaterImpl());
+        final Collection<LinkDefinition<Source, Target>> links = _linkStore.openAndLoad(new LinkStoreUpdaterImpl());
         assertEquals(1, links.size(), "Unexpected link number");
 
-        LinkDefinition<Source, Target> recoveredLink = links.iterator().next();
+        final LinkDefinition<Source, Target> recoveredLink = links.iterator().next();
 
         assertEquals(linkDefinition.getName(), recoveredLink.getName(), "Unexpected link name");
         assertEquals(linkDefinition.getRemoteContainerId(), recoveredLink.getRemoteContainerId(),
@@ -206,14 +179,14 @@
     }
 
     @Test
-    public void testDelete()
+    public void delete()
     {
         _linkStore.openAndLoad(new LinkStoreUpdaterImpl());
 
-        LinkDefinition<Source, Target> linkDefinition = createLinkDefinition("1", "test");
+        final LinkDefinition<Source, Target> linkDefinition = createLinkDefinition("1", "test");
         _linkStore.saveLink(linkDefinition);
 
-        LinkDefinition<Source, Target> linkDefinition2 = createLinkDefinition("2", "test2");
+        final LinkDefinition<Source, Target> linkDefinition2 = createLinkDefinition("2", "test2");
         _linkStore.saveLink(linkDefinition2);
 
         _linkStore.close();
@@ -232,6 +205,6 @@
 
     private LinkDefinitionImpl<Source, Target> createLinkDefinition(final String remoteContainerId, final String linkName)
     {
-        return new LinkDefinitionImpl(remoteContainerId, linkName, Role.RECEIVER, _source, _target);
+        return new LinkDefinitionImpl<>(remoteContainerId, linkName, Role.RECEIVER, _source, _target);
     }
 }
diff --git a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/type/extensions/soleconn/SoleConnectionDetectionPolicyTest.java b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/type/extensions/soleconn/SoleConnectionDetectionPolicyTest.java
index f50903e..d54110b 100644
--- a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/type/extensions/soleconn/SoleConnectionDetectionPolicyTest.java
+++ b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/type/extensions/soleconn/SoleConnectionDetectionPolicyTest.java
@@ -20,43 +20,38 @@
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
-import static org.junit.jupiter.api.Assertions.fail;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 import org.apache.qpid.server.protocol.v1_0.type.UnsignedInteger;
 import org.apache.qpid.test.utils.UnitTestBase;
 
 import org.junit.jupiter.api.Test;
 
-public class SoleConnectionDetectionPolicyTest extends UnitTestBase
+class SoleConnectionDetectionPolicyTest extends UnitTestBase
 {
     @Test
-    public void testValue()
+    void value()
     {
         assertEquals(new UnsignedInteger(0), SoleConnectionDetectionPolicy.STRONG.getValue());
         assertEquals(new UnsignedInteger(1), SoleConnectionDetectionPolicy.WEAK.getValue());
     }
 
     @Test
-    public void testValueOf()
+    void valueOf()
     {
         assertEquals(SoleConnectionDetectionPolicy.STRONG,
                 SoleConnectionDetectionPolicy.valueOf(new UnsignedInteger(0)));
         assertEquals(SoleConnectionDetectionPolicy.WEAK,
                 SoleConnectionDetectionPolicy.valueOf(new UnsignedInteger(1)));
 
-        try
-        {
-            SoleConnectionDetectionPolicy.valueOf(new UnsignedInteger(2));
-            fail("An exception is expected");
-        }
-        catch (RuntimeException e)
-        {
-            assertNotNull(e.getMessage());
-        }
+        final RuntimeException thrown = assertThrows(RuntimeException.class,
+                () -> SoleConnectionDetectionPolicy.valueOf(new UnsignedInteger(2)),
+                "An exception is expected");
+        assertNotNull(thrown.getMessage());
     }
 
     @Test
-    public void testToString()
+    void toStrings()
     {
         assertEquals("strong", SoleConnectionDetectionPolicy.STRONG.toString());
         assertEquals("weak", SoleConnectionDetectionPolicy.WEAK.toString());
diff --git a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/type/extensions/soleconn/SoleConnectionEnforcementPolicyTest.java b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/type/extensions/soleconn/SoleConnectionEnforcementPolicyTest.java
index d3a8357..61371cc 100644
--- a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/type/extensions/soleconn/SoleConnectionEnforcementPolicyTest.java
+++ b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/type/extensions/soleconn/SoleConnectionEnforcementPolicyTest.java
@@ -20,44 +20,38 @@
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
-import static org.junit.jupiter.api.Assertions.fail;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 import org.apache.qpid.server.protocol.v1_0.type.UnsignedInteger;
 import org.apache.qpid.test.utils.UnitTestBase;
 
 import org.junit.jupiter.api.Test;
 
-
-public class SoleConnectionEnforcementPolicyTest extends UnitTestBase
+class SoleConnectionEnforcementPolicyTest extends UnitTestBase
 {
     @Test
-    public void testValue()
+    void value()
     {
         assertEquals(new UnsignedInteger(0), SoleConnectionEnforcementPolicy.REFUSE_CONNECTION.getValue());
         assertEquals(new UnsignedInteger(1), SoleConnectionEnforcementPolicy.CLOSE_EXISTING.getValue());
     }
 
     @Test
-    public void testValueOf()
+    void valueOf()
     {
         assertEquals(SoleConnectionEnforcementPolicy.REFUSE_CONNECTION,
                 SoleConnectionEnforcementPolicy.valueOf(new UnsignedInteger(0)));
         assertEquals(SoleConnectionEnforcementPolicy.CLOSE_EXISTING,
                 SoleConnectionEnforcementPolicy.valueOf(new UnsignedInteger(1)));
 
-        try
-        {
-            SoleConnectionEnforcementPolicy.valueOf(new UnsignedInteger(2));
-            fail("An exception is expected");
-        }
-        catch (RuntimeException e)
-        {
-            assertNotNull(e.getMessage());
-        }
+        final RuntimeException thrown = assertThrows(RuntimeException.class,
+                () -> SoleConnectionEnforcementPolicy.valueOf(new UnsignedInteger(2)),
+                "An exception is expected");
+        assertNotNull(thrown.getMessage());
     }
 
     @Test
-    public void testToString()
+    void toStrings()
     {
         assertEquals("refuse-connection", SoleConnectionEnforcementPolicy.REFUSE_CONNECTION.toString());
         assertEquals("close-existing", SoleConnectionEnforcementPolicy.CLOSE_EXISTING.toString());
diff --git a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/type/extensions/soleconn/StrongConnectionEstablishmentLimiterTest.java b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/type/extensions/soleconn/StrongConnectionEstablishmentLimiterTest.java
index bcb3d13..396ebe0 100644
--- a/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/type/extensions/soleconn/StrongConnectionEstablishmentLimiterTest.java
+++ b/broker-plugins/amqp-1-0-protocol/src/test/java/org/apache/qpid/server/protocol/v1_0/type/extensions/soleconn/StrongConnectionEstablishmentLimiterTest.java
@@ -20,8 +20,10 @@
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
-import static org.junit.jupiter.api.Assertions.fail;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.verifyNoInteractions;
 
 import java.util.HashSet;
 import java.util.Objects;
@@ -38,27 +40,27 @@
 
 import org.mockito.Mockito;
 
-public class StrongConnectionEstablishmentLimiterTest extends UnitTestBase
+class StrongConnectionEstablishmentLimiterTest extends UnitTestBase
 {
     private StrongConnectionEstablishmentLimiter _limiter;
 
     private Registry _registry;
 
     @BeforeAll
-    public void setUp()
+    void setUp()
     {
         _registry = new Registry();
         _limiter = (StrongConnectionEstablishmentLimiter) new StrongConnectionEstablishmentLimiter().append(_registry);
     }
 
     @Test
-    public void testType()
+    void type()
     {
         assertEquals("EstablishmentPolicy.strong", _limiter.getType());
     }
 
     @Test
-    public void testNoPolicy()
+    void noPolicy()
     {
         final AMQPConnection_1_0<?> connection1 = newConnection("C", null);
         final ConnectionSlot slot1 = _limiter.register(connection1);
@@ -86,7 +88,7 @@
     }
 
     @Test
-    public void testNewConnectionWithPolicy()
+    void newConnectionWithPolicy()
     {
         final AMQPConnection_1_0<?> connection1 = newConnection("C", null);
         final ConnectionSlot slot1 = _limiter.register(connection1);
@@ -97,21 +99,18 @@
         assertTrue(_registry.isRegistered(connection2));
 
         final AMQPConnection_1_0<?> connection3 = newConnection("C", SoleConnectionEnforcementPolicy.REFUSE_CONNECTION);
-        try
-        {
-            _limiter.register(connection3);
-            fail("A sole connection enforcement policy exception is expected");
-        }
-        catch (SoleConnectionEnforcementPolicyException e)
-        {
-            assertEquals("Single connection with container ID 'C' is required due to sole connection enforcement policy 'refuse-connection'",
-                    e.getMessage());
 
-            assertEquals(2, e.getExistingConnections().size());
-            assertTrue(e.getExistingConnections().contains(connection1));
-            assertTrue(e.getExistingConnections().contains(connection2));
-            assertEquals(SoleConnectionEnforcementPolicy.REFUSE_CONNECTION, e.getPolicy());
-        }
+        final SoleConnectionEnforcementPolicyException thrown = assertThrows(SoleConnectionEnforcementPolicyException.class,
+                () -> _limiter.register(connection3),
+                "A sole connection enforcement policy exception is expected");
+
+        assertEquals("Single connection with container ID 'C' is required due to sole connection enforcement policy 'refuse-connection'",
+                thrown.getMessage());
+
+        assertEquals(2, thrown.getExistingConnections().size());
+        assertTrue(thrown.getExistingConnections().contains(connection1));
+        assertTrue(thrown.getExistingConnections().contains(connection2));
+        assertEquals(SoleConnectionEnforcementPolicy.REFUSE_CONNECTION, thrown.getPolicy());
 
         slot2.free();
         assertFalse(_registry.isRegistered(connection2));
@@ -123,27 +122,24 @@
     }
 
     @Test
-    public void testExistingConnectionWithPolicy()
+    void existingConnectionWithPolicy()
     {
         final AMQPConnection_1_0<?> connection1 = newConnection("C", SoleConnectionEnforcementPolicy.CLOSE_EXISTING);
         final ConnectionSlot slot1 = _limiter.register(connection1);
         assertTrue(_registry.isRegistered(connection1));
 
         final AMQPConnection_1_0<?> connection2 = newConnection("C", SoleConnectionEnforcementPolicy.REFUSE_CONNECTION);
-        try
-        {
-            _limiter.register(connection2);
-            fail("A sole connection enforcement policy exception is expected");
-        }
-        catch (SoleConnectionEnforcementPolicyException e)
-        {
-            assertEquals("Single connection with container ID 'C' is required due to sole connection enforcement policy 'close-existing'",
-                    e.getMessage());
 
-            assertEquals(1, e.getExistingConnections().size());
-            assertTrue(e.getExistingConnections().contains(connection1));
-            assertEquals(SoleConnectionEnforcementPolicy.CLOSE_EXISTING, e.getPolicy());
-        }
+        final SoleConnectionEnforcementPolicyException thrown = assertThrows(SoleConnectionEnforcementPolicyException.class,
+                () -> _limiter.register(connection2),
+                "A sole connection enforcement policy exception is expected");
+
+        assertEquals("Single connection with container ID 'C' is required due to sole connection enforcement policy 'close-existing'",
+                thrown.getMessage());
+
+        assertEquals(1, thrown.getExistingConnections().size());
+        assertTrue(thrown.getExistingConnections().contains(connection1));
+        assertEquals(SoleConnectionEnforcementPolicy.CLOSE_EXISTING, thrown.getPolicy());
 
         slot1.free();
         assertFalse(_registry.isRegistered(connection1));
@@ -151,14 +147,14 @@
     }
 
     @Test
-    public void testExistingClosedConnectionWithPolicy()
+    void existingClosedConnectionWithPolicy()
     {
         final AMQPConnection_1_0<?> connection1 = newConnection("C", SoleConnectionEnforcementPolicy.CLOSE_EXISTING);
-        Mockito.doReturn(false).when(connection1).isClosing();
+        doReturn(false).when(connection1).isClosing();
         final ConnectionSlot slot1 = _limiter.register(connection1);
         assertTrue(_registry.isRegistered(connection1));
 
-        Mockito.doReturn(true).when(connection1).isClosing();
+        doReturn(true).when(connection1).isClosing();
         final AMQPConnection_1_0<?> connection2 = newConnection("C", SoleConnectionEnforcementPolicy.CLOSE_EXISTING);
         final ConnectionSlot slot2 = _limiter.register(connection2);
         assertTrue(_registry.isRegistered(connection2));
@@ -173,14 +169,14 @@
     }
 
     @Test
-    public void testClosedConnection()
+    void closedConnection()
     {
         final AMQPConnection_1_0<?> connection1 = newConnection("C", SoleConnectionEnforcementPolicy.REFUSE_CONNECTION);
         final ConnectionSlot slot1 = _limiter.register(connection1);
         assertTrue(_registry.isRegistered(connection1));
 
         final AMQPConnection_1_0<?> connection2 = newConnection("C", SoleConnectionEnforcementPolicy.CLOSE_EXISTING);
-        Mockito.doReturn(true).when(connection1).isClosing();
+        doReturn(true).when(connection1).isClosing();
         final ConnectionSlot slot2 = _limiter.register(connection2);
         assertTrue(_registry.isRegistered(connection2));
 
@@ -194,33 +190,30 @@
     }
 
     @Test
-    public void testNewConnectionWithPolicy_ClosedExisting()
+    void newConnectionWithPolicy_ClosedExisting()
     {
         final AMQPConnection_1_0<?> connection1 = newConnection("C", SoleConnectionEnforcementPolicy.REFUSE_CONNECTION);
-        Mockito.doReturn(false).when(connection1).isClosing();
+        doReturn(false).when(connection1).isClosing();
         final ConnectionSlot slot1 = _limiter.register(connection1);
         assertTrue(_registry.isRegistered(connection1));
 
-        Mockito.doReturn(true).when(connection1).isClosing();
+        doReturn(true).when(connection1).isClosing();
         final AMQPConnection_1_0<?> connection2 = newConnection("C", null);
         final ConnectionSlot slot2 = _limiter.register(connection2);
         assertTrue(_registry.isRegistered(connection2));
 
         final AMQPConnection_1_0<?> connection3 = newConnection("C", SoleConnectionEnforcementPolicy.CLOSE_EXISTING);
-        try
-        {
-            _limiter.register(connection3);
-            fail("A sole connection enforcement policy exception is expected");
-        }
-        catch (SoleConnectionEnforcementPolicyException e)
-        {
-            assertEquals("Single connection with container ID 'C' is required due to sole connection enforcement policy 'close-existing'",
-                    e.getMessage());
 
-            assertEquals(1, e.getExistingConnections().size());
-            assertTrue(e.getExistingConnections().contains(connection2));
-            assertEquals(SoleConnectionEnforcementPolicy.CLOSE_EXISTING, e.getPolicy());
-        }
+        final SoleConnectionEnforcementPolicyException thrown = assertThrows(SoleConnectionEnforcementPolicyException.class,
+                () -> _limiter.register(connection3),
+                "A sole connection enforcement policy exception is expected");
+
+        assertEquals("Single connection with container ID 'C' is required due to sole connection enforcement policy 'close-existing'",
+                thrown.getMessage());
+
+        assertEquals(1, thrown.getExistingConnections().size());
+        assertTrue(thrown.getExistingConnections().contains(connection2));
+        assertEquals(SoleConnectionEnforcementPolicy.CLOSE_EXISTING, thrown.getPolicy());
 
         slot2.free();
         assertFalse(_registry.isRegistered(connection2));
@@ -232,33 +225,30 @@
     }
 
     @Test
-    public void testNewConnectionWithPolicy2_ClosedExisting()
+    void newConnectionWithPolicy2_ClosedExisting()
     {
         final AMQPConnection_1_0<?> connection1 = newConnection("C", SoleConnectionEnforcementPolicy.REFUSE_CONNECTION);
-        Mockito.doReturn(false).when(connection1).isClosing();
+        doReturn(false).when(connection1).isClosing();
         final ConnectionSlot slot1 = _limiter.register(connection1);
         assertTrue(_registry.isRegistered(connection1));
 
-        Mockito.doReturn(true).when(connection1).isClosing();
+        doReturn(true).when(connection1).isClosing();
         final AMQPConnection_1_0<?> connection2 = newConnection("C", SoleConnectionEnforcementPolicy.REFUSE_CONNECTION);
         final ConnectionSlot slot2 = _limiter.register(connection2);
         assertTrue(_registry.isRegistered(connection2));
 
         final AMQPConnection_1_0<?> connection3 = newConnection("C", SoleConnectionEnforcementPolicy.CLOSE_EXISTING);
-        try
-        {
-            _limiter.register(connection3);
-            fail("A sole connection enforcement policy exception is expected");
-        }
-        catch (SoleConnectionEnforcementPolicyException e)
-        {
-            assertEquals("Single connection with container ID 'C' is required due to sole connection enforcement policy 'refuse-connection'",
-                    e.getMessage());
 
-            assertEquals(1, e.getExistingConnections().size());
-            assertTrue(e.getExistingConnections().contains(connection2));
-            assertEquals(SoleConnectionEnforcementPolicy.REFUSE_CONNECTION, e.getPolicy());
-        }
+        final SoleConnectionEnforcementPolicyException thrown = assertThrows(SoleConnectionEnforcementPolicyException.class,
+                () -> _limiter.register(connection3),
+                "A sole connection enforcement policy exception is expected");
+
+        assertEquals("Single connection with container ID 'C' is required due to sole connection enforcement policy 'refuse-connection'",
+                thrown.getMessage());
+
+        assertEquals(1, thrown.getExistingConnections().size());
+        assertTrue(thrown.getExistingConnections().contains(connection2));
+        assertEquals(SoleConnectionEnforcementPolicy.REFUSE_CONNECTION, thrown.getPolicy());
 
         slot2.free();
         assertFalse(_registry.isRegistered(connection2));
@@ -270,7 +260,7 @@
     }
 
     @Test
-    public void testAnotherConnectionType()
+    void anotherConnectionType()
     {
         final AMQPConnection<?> connection = Mockito.mock(AMQPConnection.class);
         final ConnectionSlot slot = _limiter.register(connection);
@@ -278,11 +268,11 @@
         slot.free();
         assertFalse(_registry.isRegistered(connection));
         assertTrue(_registry.hasBeenRegistered(connection));
-        Mockito.verifyNoInteractions(connection);
+        verifyNoInteractions(connection);
     }
 
     @Test
-    public void testMultipleIndependentConnections()
+    void multipleIndependentConnections()
     {
         final AMQPConnection_1_0<?> connection1 = newConnection("C1", null);
         final ConnectionSlot slot1 = _limiter.register(connection1);
@@ -310,7 +300,7 @@
     }
 
     @Test
-    public void testMultipleIndependentConnections2()
+    void multipleIndependentConnections2()
     {
         final AMQPConnection_1_0<?> connection1 = newConnection(null, null);
         final ConnectionSlot slot1 = _limiter.register(connection1);
@@ -340,17 +330,15 @@
     private AMQPConnection_1_0<?> newConnection(String id, SoleConnectionEnforcementPolicy policy)
     {
         final AMQPConnection_1_0<?> connection = Mockito.mock(AMQPConnection_1_0.class);
-        Mockito.doReturn(id).when(connection).getRemoteContainerId();
-        Mockito.doReturn(policy).when(connection).getSoleConnectionEnforcementPolicy();
+        doReturn(id).when(connection).getRemoteContainerId();
+        doReturn(policy).when(connection).getSoleConnectionEnforcementPolicy();
         return connection;
     }
 
     static final class Registry implements ConnectionLimiter
     {
         private final Set<AMQPConnection<?>> _registered;
-
         private final Set<AMQPConnection<?>> _connections;
-
         private final ConnectionLimiter _subLimiter;
 
         public Registry()
@@ -360,7 +348,7 @@
             _subLimiter = ConnectionLimiter.noLimits();
         }
 
-        private Registry(Registry limiter, ConnectionLimiter subLimiter)
+        private Registry(final Registry limiter, final ConnectionLimiter subLimiter)
         {
             _registered = limiter._registered;
             _connections = limiter._connections;
@@ -377,17 +365,17 @@
         }
 
         @Override
-        public ConnectionLimiter append(ConnectionLimiter limiter)
+        public ConnectionLimiter append(final ConnectionLimiter limiter)
         {
             return new Registry(this, _subLimiter.append(limiter));
         }
 
-        public boolean isRegistered(AMQPConnection<?> connection)
+        public boolean isRegistered(final AMQPConnection<?> connection)
         {
             return _connections.contains(connection);
         }
 
-        public boolean hasBeenRegistered(AMQPConnection<?> connection)
+        public boolean hasBeenRegistered(final AMQPConnection<?> connection)
         {
             return _registered.contains(connection);
         }