@Override
  public synchronized void snapshot(MetricsRecordBuilder metricsRecordBuilder, boolean all) {
    // Get a reference to the old histogram.
    Snapshot snapshot = histogram.snapshot();
    if (snapshot != null) {
      updateSnapshotMetrics(name, desc, histogram, snapshot, metricsRecordBuilder);
      updateSnapshotRangeMetrics(metricsRecordBuilder, snapshot);
    }
  }
Returns the ranges to be counted
hbase-hadoop-compat/src/main/java/org/apache/hadoop/metrics2/lib/MutableRangeHistogram.java