synchronized void add(String name, MutableMetric metric) {
    addNewMetricIfAbsent(name, metric, MutableMetric.class);
  }
Create a new histogram with size range counts.
@param name The name of the histogram
@param desc The description of the data in the histogram.
@return A new MutableSizeHistogram
hbase-hadoop-compat/src/main/java/org/apache/hadoop/metrics2/lib/DynamicMetricsRegistry.java