JsonResponse::merge

public function merge(ProtobufMessage $message)
    {
        if ( ! $message instanceof BitrixPullProtobufJsonResponse) {
            throw new InvalidArgumentException(sprintf('Argument 1 passed to %s must be a %s, %s given', __METHOD__, __CLASS__, get_class($message)));
        }

        $this->json = ($message->json !== null) ? $message->json : $this->json;
    }