protected RegionLocator getRegionLocator() {
    if (regionLocator == null) {
      throw new IllegalStateException(NOT_INITIALIZED);
    }
    return regionLocator;
  }
Allows subclasses to get the {@link RegionLocator}.
hbase-mapreduce/src/main/java/org/apache/hadoop/hbase/mapreduce/TableInputFormatBase.java