private static double getRegionSizeMB(final MasterServices masterServices,
    final RegionInfo regionInfo) {
    final ServerName sn =
      masterServices.getAssignmentManager().getRegionStates().getRegionServerOfRegion(regionInfo);
    final RegionMetrics regionLoad = masterServices.getServerManager().getLoad(sn)
      .getRegionMetrics().get(regionInfo.getRegionName());
    if (regionLoad == null) {
      LOG.debug("{} was not found in RegionsLoad", regionInfo.getRegionNameAsString());
      return -1;
    }
    return regionLoad.getStoreFileSize().get(Size.Unit.MEGABYTE);
  }
A test for when a region is the target of both a split and a merge plan. Does not define
expected behavior, only that some change is applied to the table.
hbase-server/src/test/java/org/apache/hadoop/hbase/master/normalizer/TestSimpleRegionNormalizerOnCluster.java