code: public static int findTab(byte [] utf) {
      return org.apache.hadoop.util.UTF8ByteArrayUtils.findNthByte(utf, 0, 
          utf.length, (byte)'\t', 1);
    }
docs: Find the first occured tab in a UTF-8 encoded string
  @param utf a byte array containing a UTF-8 encoded string
  @return position that first tab occures otherwise -1