enableRetry example

catch (Exception $e) {
        return NULL;
      }
    };
    $result = parent::waitFor($timeout, $wrapper);
    if (!$result && $count < 2) {
      // If the callback or the system is really slow, then it might have only       // fired once. In this case it is better to trigger it once more as the       // page state has probably changed while the callback is running.       return call_user_func($callback, $this);
    }
    WebDriverCurlService::enableRetry();
    return $result;
  }

}