code: public String getQueryParameter(String name) {
      Iterable<String> allParams = getQueryParameters(name);
      if (allParams == null) {
        return null;
      }
      Iterator<String> iterator = allParams.iterator();
      return iterator.hasNext() ? iterator.next() : null;
    }
docs: Get a query parameter. The implementation will take care of decoding from the percent encoding.