@Override
    public void handleRegionStartKeyNotEmpty(HbckRegionInfo hi) throws IOException {
      errors.reportError(HbckErrorReporter.ERROR_CODE.FIRST_REGION_STARTKEY_NOT_EMPTY,
        "First region should start with an empty key.  You need to "
          + " create a new region and regioninfo in HDFS to plug the hole.",
        getTableInfo(), hi);
    }
Returns descriptor common to all regions. null if are none or multiple!
hbase-server/src/main/java/org/apache/hadoop/hbase/util/HbckTableInfo.java