private long getCounterValue(String suffix) {
    return counters.get(HelixClusterManager.class.getName() + "." + suffix).getCount();
  }
Get the counter value for the metric in {@link HelixClusterManagerMetrics} with the given suffix.
@param suffix the suffix of the metric that distinguishes it from other metrics in the class.
@return the value of the counter.
ambry-clustermap/src/test/java/com/github/ambry/clustermap/HelixClusterManagerTest.java