@After
  public void tearDown() {
    for (VM vm : toArray(managerVM, memberVM)) {
      vm.invoke(() -> {
        removeListener(messageListener);
        cache.close();
        cache = null;
        logger = null;
        messageListener = null;
        distributedSystemMXBean = null;
        alertingService = null;
      });
    }
  }
Distributed tests for {@link AlertingService} with {@link DistributedSystemMXBean} in the JMX
Manager without any {@code NotificationListener}s.
geode-core/src/distributedTest/java/org/apache/geode/alerting/internal/api/AlertingServiceWithoutListenerDistributedTest.java