@VisibleForTesting
  public int getLabelsToNodesFailedRetrieved() {
    return numGetLabelsToNodesFailedRetrieved.value();
  }
@Test
  public void testGetLabelsToNodesFailed() {
    long totalBadBefore = metrics.getLabelsToNodesFailedRetrieved();
    badSubCluster.getLabelToNodes();
    Assert.assertEquals(totalBadBefore + 1, metrics.getLabelsToNodesFailedRetrieved());
  }