public void succeededSignalToContainerRetrieved(long duration) {
    totalSucceededSignalToContainerRetrieved.add(duration);
    signalToContainerLatency.add(duration);
  }
@Test
  public void testSucceededSignalToContainerRetrieved() {
    long totalGoodBefore = metrics.getNumSucceededSignalToContainerRetrieved();
    goodSubCluster.getSignalToContainerTimeouts(150);
    Assert.assertEquals(totalGoodBefore + 1,
        metrics.getNumSucceededSignalToContainerRetrieved());
    Assert.assertEquals(150,
        metrics.getLatencySucceededSignalToContainerRetrieved(), ASSERT_DOUBLE_DELTA);
    goodSubCluster.getSignalToContainerTimeouts(300);
    Assert.assertEquals(totalGoodBefore + 2,
        metrics.getNumSucceededSignalToContainerRetrieved());
    Assert.assertEquals(225,
        metrics.getLatencySucceededSignalToContainerRetrieved(), ASSERT_DOUBLE_DELTA);
  }