private function checkUserRateLimit(ResponseInterface $response)
    {
        $userRemaining = $response->getHeaderLine('X-RateLimit-UserRemaining');
        $userLimit = $response->getHeaderLine('X-RateLimit-UserLimit');

        if ('' !== $userRemaining && $userRemaining < 1) {
            throw new RateLimitException('No user credits available. The limit is ' . $userLimit);
        }
    }