docs: private static String joinStrings(final Set tags, final String delim) {
          ArrayList<String> strings = new ArrayList<String>(tags);
          String[] objects = strings.toArray(new String[strings.size()]);
          Arrays.sort(objects);
          final StringBuffer sb = new StringBuffer();
          for (final String tag : objects) {
              if (sb.length() > 0) {
                  sb.append(delim);
              }
              sb.append(tag);
          }
  
          return sb.toString();
      }