code: public static String join(final Collection<String> chunks,
      final String delimiter) {
      StringBuilder sb = new StringBuilder();
      if (!chunks.isEmpty()) {
        Iterator<String> itr = chunks.iterator();
        sb.append(itr.next());
        while (itr.hasNext()) {
          sb.append(delimiter);
          sb.append(itr.next());
        }
      }
      return sb.toString();
    }
docs: Join a collection of strings together into one.
  
  @param chunks the chunks to join.
  @param delimiter the delimiter between the keys.
  @return the fully joined string.