docs: public static byte[] getTSUIDFromKey(final byte[] row_key, 
        final short metric_width, final short timestamp_width) {
      int idx = 0;
      // validation
      final int tag_pair_width = TSDB.tagk_width() + TSDB.tagv_width();
      final int tags_length = row_key.length - 
          (Const.SALT_WIDTH() + metric_width + timestamp_width);
      if (tags_length < tag_pair_width || (tags_length % tag_pair_width) != 0) {
        throw new IllegalArgumentException(
            "Row key is missing tags or it is corrupted " + Arrays.toString(row_key));
      }
      final byte[] tsuid = new byte[
                   row_key.length - timestamp_width - Const.SALT_WIDTH()];
      for (int i = Const.SALT_WIDTH(); i < row_key.length; i++) {
        if (i < Const.SALT_WIDTH() + metric_width || 
            i >= (Const.SALT_WIDTH() + metric_width + timestamp_width)) {
          tsuid[idx] = row_key[i];
          idx++;
        }
      }
      return tsuid;
    }