requestCallback = $requestCallback; $this->responseCallback = $responseCallback; } public function canCacheRequest(RequestInterface $request) { return $this->requestCallback ? call_user_func($this->requestCallback, $request) : parent::canCacheRequest($request); } public function canCacheResponse(Response $response) { return $this->responseCallback ? call_user_func($this->responseCallback, $response) : parent::canCacheResponse($response); } }