private function assert(HttpClient $client, RequestFactory $requestFactory, RequestInterface $request, ResponseInterface $response, string $method, string $body = null)
    {
        $client->sendRequest($request)->shouldBeCalled()->willReturn($response);
        $this->mockFactory($requestFactory, $request, strtoupper($method), $body);

        $this->$method(self::$requestData['uri'], self::$requestData['headers'], self::$requestData['body'])->shouldReturnAnInstanceOf(ResponseInterface::class);
    }