code: public static String encodeQueryString(String queryString) {
          if (StringUtils.isBlank(queryString)) {
              return queryString;
          }
          return new QueryString(queryString).toString();
      }
docs: <p>URL-Encodes the query string portion of a URL. The entire
  string supplied is assumed to be a query string.
  @param queryString URL query string
  @return encoded path
  @since 1.8.0