* @param extended produce extended stat (stdev, min/max etc.) if true.
* @return a new metric object
*/
public MetricMutableStat newStat(String name, String description,
String sampleName, String valueName, boolean extended) {
MetricMutableStat ret = mf.newStat(name, description, sampleName,
valueName, extended);
return addNewMetricIfAbsent(name, ret, MetricMutableStat.class);
}