public function onError(GetResponseForExceptionEvent $event)
    {
        if ($event->getRequest()->isXmlHttpRequest()) {
            $exception = $event->getException();
            if ($exception instanceof InvalidDataException) {
                // return correct status code for invalid data sent by the user
                $response = new JsonResponse($exception->getErrors(), 422);
            } else {
                $response = new JsonResponse([
                    'message' => $exception->getMessage(),
                    'trace' => $exception->getTrace(),
                    //if <200, not http error code
                ], $exception->getCode() < 200 ? 500 : $exception->getCode());
            }

            $event->setResponse($response);
        }
    }