docs: public static byte[] extractQualifier(final byte[] qualifier, 
        final int offset) {
      validateQualifier(qualifier, offset);
      if ((qualifier[offset] & Const.MS_BYTE_FLAG) == Const.MS_BYTE_FLAG) {
        return new byte[] { qualifier[offset], qualifier[offset + 1],
            qualifier[offset + 2], qualifier[offset + 3] };
      } else {
        return new byte[] { qualifier[offset], qualifier[offset + 1] };
      }
    }