code: public String getQueryStringParam(final String paramname) {
      final List<String> params = getQueryString().get(paramname);
      return params == null ? null : params.get(params.size() - 1);
    }
docs: Returns the value of the given query string parameter.
  <p>
  If this parameter occurs multiple times in the URL, only the last value
  is returned and others are silently ignored.
  @param paramname Name of the query string parameter to get.
  @return The value of the parameter or {@code null} if this parameter
  wasn't passed in the URI.