@After
  public void tearDown() {
    disconnectAllFromDS();
    invokeInEveryVM(() -> {
      regionDestroyedInvoked = false;
      myCache = null;
      alertReceived = false;
    });
    assertThat(executorService.shutdownNow()).isEmpty();
  }
This class tests the functionality of the {@link ClusterDistributionManager} class.
geode-core/src/distributedTest/java/org/apache/geode/distributed/internal/ClusterDistributionManagerDUnitTest.java