private String readNext(final boolean allowEnd) {
      int idxNext = is.indexOf(separator, idx);
      if (idxNext == -1) {
        if (allowEnd) {
          return StringUtil.unescapeXmlEntities(is.substring(idx));
        }
      }
      final String s = is.substring(idx, idxNext);
      idx = idxNext + separator.length();
      return s;
    }
private String readNext(final boolean allowEnd)