docs: function (url, force) {
              if (force || this._timestampURL[url]) {
                  var timestamp = (new Date()).getTime();
                  if (url.indexOf("?") != -1) {
                      return url + "&timestamp=" + timestamp;
                  } else {
                      return url + "?timestamp=" + timestamp;
                  }
              } else {
                  return url;
              }
          }