@Override
  public final void postTearDownCacheTestCase() throws Exception {
    Invoke.invokeInEveryVM(new SerializableRunnable() {
      @Override
      public void run() {
        InternalResourceManager.setResourceObserver(null);
      }
    });
    InternalResourceManager.setResourceObserver(null);
  }
Test for hang condition observed with the PRHARedundancyProvider.createMissingBuckets code.

A parent region is populated with buckets. Then the child region is created simultaneously on
several nodes.
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/execute/PRColocationDUnitTest.java