GEODE-7319: Solution for flaky test
diff --git a/geode-core/src/main/java/org/apache/geode/internal/cache/tier/sockets/CacheClientNotifier.java b/geode-core/src/main/java/org/apache/geode/internal/cache/tier/sockets/CacheClientNotifier.java
index 7395ea7..40abfa2 100755
--- a/geode-core/src/main/java/org/apache/geode/internal/cache/tier/sockets/CacheClientNotifier.java
+++ b/geode-core/src/main/java/org/apache/geode/internal/cache/tier/sockets/CacheClientNotifier.java
@@ -162,6 +162,11 @@
     return ccnSingleton;
   }
 
+  @VisibleForTesting
+  public static void resetInstance() {
+    ccnSingleton = null;
+  }
+
   /**
    * Registers a new client updater that wants to receive updates with this server.
    *
diff --git a/geode-core/src/test/java/org/apache/geode/internal/cache/BucketRegionTest.java b/geode-core/src/test/java/org/apache/geode/internal/cache/BucketRegionTest.java
index 2042557..4293c3e 100644
--- a/geode-core/src/test/java/org/apache/geode/internal/cache/BucketRegionTest.java
+++ b/geode-core/src/test/java/org/apache/geode/internal/cache/BucketRegionTest.java
@@ -456,6 +456,8 @@
     doReturn(false).when(partitionedRegion).isInitialized();
     doReturn(true).when(partitionedRegion).shouldDispatchListenerEvent();
 
+    CacheClientNotifier.resetInstance();
+
     bucketRegion.invokeDestroyCallbacks(EnumListenerEvent.AFTER_DESTROY, event, false, false);
 
     verify(partitionedRegion, never()).invokeDestroyCallbacks(EnumListenerEvent.AFTER_DESTROY,
@@ -503,6 +505,8 @@
     doReturn(false).when(partitionedRegion).isInitialized();
     doReturn(true).when(partitionedRegion).shouldDispatchListenerEvent();
 
+    CacheClientNotifier.resetInstance();
+
     bucketRegion.invokeInvalidateCallbacks(EnumListenerEvent.AFTER_INVALIDATE, event, false);
 
     verify(partitionedRegion, never()).invokeInvalidateCallbacks(EnumListenerEvent.AFTER_INVALIDATE,
@@ -550,6 +554,8 @@
     doReturn(false).when(partitionedRegion).isInitialized();
     doReturn(true).when(partitionedRegion).shouldDispatchListenerEvent();
 
+    CacheClientNotifier.resetInstance();
+
     bucketRegion.invokePutCallbacks(EnumListenerEvent.AFTER_CREATE, event, false, false);
 
     verify(partitionedRegion, never()).invokePutCallbacks(EnumListenerEvent.AFTER_CREATE, event,