public MutableGaugeLong newGauge(String name, String desc, long iVal) {
    return newGauge(new MetricsInfoImpl(name, desc), iVal);
  }
Create a mutable long integer gauge
@param name of the metric
@param desc metric description
@param iVal initial value
@return a new gauge object
hbase-hadoop-compat/src/main/java/org/apache/hadoop/metrics2/lib/DynamicMetricsRegistry.java