private boolean isMasterSwitchEnabled(final MasterSwitchType masterSwitchType) {
    return masterServices.isSplitOrMergeEnabled(masterSwitchType);
  }
Returns size of region in MB and if region is not found than -1
hbase-server/src/main/java/org/apache/hadoop/hbase/master/normalizer/SimpleRegionNormalizer.java