@Override
      public Object call() throws Exception {
        InternalCache gfCache = getCache();
        gfCache.getInternalResourceManager().getHeapMonitor().updateStateAndSendEvent(850, "test");
        return null;
      }
Make sure appropriate events are delivered when moving between states.
geode-core/src/distributedTest/java/org/apache/geode/cache/management/MemoryThresholdsDUnitTest.java