private static void confirmNoCacheListenerInvalidates() throws Exception {
    // Confirm there are no EventCountingCacheListener invalidate events.
    // These would be coming from the subscription channel.
    Region region = cache.getRegion(REGION_NAME);
    EventCountingCacheListener cacheListener =
        (EventCountingCacheListener) region.getAttributes().getCacheListener();
    assertEquals(0/* expected */, cacheListener.getInvalidates()/* actual */);
  }
wait for queues to drain in the server
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/tier/sockets/InterestListDUnitTest.java