@Override
  public ReturnCode filterCell(final Cell cell) {
    if (null != cell && cell instanceof ExtendedCell) {
      // If a cell with a mob reference tag, it's included.
      if (MobUtils.isMobReferenceCell((ExtendedCell) cell)) {
        return ReturnCode.INCLUDE;
      }
    }
    return ReturnCode.SKIP;
  }
A filter that returns the cells which have mob reference tags. It's a server-side filter.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/MobReferenceOnlyFilter.java