fix unit test to desired behavior: register overlay resource provider with higher service ranking
with osgi-mock 1.4.0 it worked before because this hat a flaw in comparing service references
diff --git a/src/test/java/org/apache/sling/resourceresolver/impl/Fixture.java b/src/test/java/org/apache/sling/resourceresolver/impl/Fixture.java
index b79ec3a..a4a1eda 100644
--- a/src/test/java/org/apache/sling/resourceresolver/impl/Fixture.java
+++ b/src/test/java/org/apache/sling/resourceresolver/impl/Fixture.java
@@ -27,6 +27,7 @@
 import org.apache.sling.resourceresolver.impl.providers.ResourceProviderInfo;
 import org.apache.sling.spi.resource.provider.ResourceProvider;
 import org.osgi.framework.BundleContext;
+import org.osgi.framework.Constants;
 import org.osgi.framework.InvalidSyntaxException;
 import org.osgi.framework.ServiceReference;
 import org.osgi.framework.ServiceRegistration;
@@ -43,12 +44,21 @@
         this.bc = bc;
     }
 
-    public ResourceProviderInfo registerResourceProvider(ResourceProvider<?> rp, String root, AuthType authType) throws InvalidSyntaxException {
+    public ResourceProviderInfo registerResourceProvider(ResourceProvider<?> rp, String root, 
+            AuthType authType) throws InvalidSyntaxException {
+        return registerResourceProvider(rp,  root, authType, 0);
+    }
+
+    public ResourceProviderInfo registerResourceProvider(ResourceProvider<?> rp, String root, 
+            AuthType authType, int serviceRanking) throws InvalidSyntaxException {
         
-        Dictionary<String, String> props = new Hashtable<String, String>();
+        Dictionary<String, Object> props = new Hashtable<>();
         props.put(ResourceProvider.PROPERTY_ROOT, root);
         props.put(ResourceProvider.PROPERTY_AUTHENTICATE, authType.name());
         props.put(ResourceProvider.PROPERTY_MODIFIABLE, Boolean.TRUE.toString());
+        if (serviceRanking != 0) {
+            props.put(Constants.SERVICE_RANKING, serviceRanking);
+        }
         
         ServiceRegistration registration = bc.registerService(ResourceProvider.class.getName(), rp, props);
         
diff --git a/src/test/java/org/apache/sling/resourceresolver/impl/providers/ResourceProviderTrackerTest.java b/src/test/java/org/apache/sling/resourceresolver/impl/providers/ResourceProviderTrackerTest.java
index 9467690..d0ed944 100644
--- a/src/test/java/org/apache/sling/resourceresolver/impl/providers/ResourceProviderTrackerTest.java
+++ b/src/test/java/org/apache/sling/resourceresolver/impl/providers/ResourceProviderTrackerTest.java
@@ -199,10 +199,10 @@
         addedCalled.set(false);
         removedCalled.set(false);
 
-        // add overlay provider
+        // add overlay provider with higher service ranking
         @SuppressWarnings("unchecked")
         ResourceProvider<Object> rp2 = mock(ResourceProvider.class);
-        final ResourceProviderInfo infoOverlay = fixture.registerResourceProvider(rp2, "/", AuthType.no);
+        final ResourceProviderInfo infoOverlay = fixture.registerResourceProvider(rp2, "/", AuthType.no, 1000);
 
         // check added and removed is called
         assertTrue(addedCalled.get());