public function createResponse(ViewHandler $handler, View $view, Request $request, $format)
    {
        $response = $handler->createResponse($view, $request, 'json');

        if ($response->isSuccessful()) {
            $callback = $this->getCallback($request);
            $response->setContent(sprintf('/**/%s(%s)', $callback, $response->getContent()));
            $response->headers->set('Content-Type', $request->getMimeType($format));
        }

        return $response;
    }