@Override
  public MetricsRegionSource createRegion(MetricsRegionWrapper wrapper) {
    return new MetricsRegionSourceImpl(wrapper, getRegionAggregate());
  }
Factory to create MetricsRegionServerSource when given a MetricsRegionServerWrapper
hbase-hadoop-compat/src/main/java/org/apache/hadoop/hbase/regionserver/MetricsRegionServerSourceFactoryImpl.java