@VisibleForTesting
  public int getClusterNodesFailedRetrieved() {
    return numGetClusterNodesFailedRetrieved.value();
  }
@Test
  public void testGetClusterNodesFailed() {
    long totalBadBefore = metrics.getClusterNodesFailedRetrieved();
    badSubCluster.getClusterNodes();
    Assert.assertEquals(totalBadBefore + 1, metrics.getClusterNodesFailedRetrieved());
  }