public Counter getFailedCounter() {
    return failedCounter;
  }
TODO: As of now, Metrics description cannot be added/ registered with {@link MetricRegistry}.
As metric names are unambiguous but concise, descriptions of metrics need to be made
available someplace for users.
hbase-hadoop-compat/src/main/java/org/apache/hadoop/hbase/metrics/OperationMetrics.java