public MutableStat newStat(String name, String desc, String sampleName, String valueName,
    boolean extended) {
    MutableStat ret = new MutableStat(name, desc, sampleName, valueName, extended);
    return addNewMetricIfAbsent(name, ret, MutableStat.class);
  }
Create a mutable metric with stats
@param name       of the metric
@param desc       metric description
@param sampleName of the metric (e.g., "Ops")
@param valueName  of the metric (e.g., "Time" or "Latency")
@param extended   produce extended stat (stdev, min/max etc.) if true.
@return a new mutable stat metric object
hbase-hadoop-compat/src/main/java/org/apache/hadoop/metrics2/lib/DynamicMetricsRegistry.java