@VisibleForTesting
  public int getSignalToContainerFailedRetrieved() {
    return numSignalToContainerFailedRetrieved.value();
  }
@Test
  public void testSignalToContainerFailed() {
    long totalBadBefore = metrics.getSignalToContainerFailedRetrieved();
    badSubCluster.getSignalContainer();
    Assert.assertEquals(totalBadBefore + 1,
        metrics.getSignalToContainerFailedRetrieved());
  }