@Override
  public void stop() {
    if (!getExecutor().isShutdown()) {
      getExecutor().shutdown();
    }
  }
Class to handle the ScheduledExecutorService{@link ScheduledExecutorService} used by
MetricsRegionAggregateSourceImpl, and JmxCacheBuster
hbase-hadoop-compat/src/main/java/org/apache/hadoop/metrics2/lib/MetricsExecutorImpl.java