@Override
  public void updateNumTablesInSpaceQuotaViolation(long numTablesInViolation) {
    tablesViolatingQuotasGauge.set(numTablesInViolation);
  }
Implementation of {@link MetricsMasterQuotaSource} which writes the values passed in via the
interface to the metrics backend.
hbase-hadoop-compat/src/main/java/org/apache/hadoop/hbase/master/MetricsMasterQuotaSourceImpl.java