whole_func_string: function addTimestamp(url) {
    var timestamp = "timestamp=".concat(new Date().getTime());
    return url + (url.indexOf('?') === -1 ? '?' : '&') + timestamp;
  }
func_code_string: function addTimestamp(url) {
    var timestamp = "timestamp=".concat(new Date().getTime());
    return url + (url.indexOf('?') === -1 ? '?' : '&') + timestamp;
  }
func_documentation_string: Add timestamp to the given URL.
  @param {string} url - The target URL.
  @returns {string} The result URL.