GuzzleHttp\Test\Handler\StreamHandlerTest::testInvokesOnStatsOnSuccess PHP Method

    public function testInvokesOnStatsOnSuccess()
    {
        Server::flush();
        Server::enqueue([new Psr7\Response(200)]);
        $req = new Psr7\Request('GET', Server::$url);
        $gotStats = null;
        $handler = new StreamHandler();
        $promise = $handler($req, ['on_stats' => function (TransferStats $stats) use(&$gotStats) {
            $gotStats = $stats;
        }]);
        $response = $promise->wait();
        $this->assertEquals(200, $response->getStatusCode());
        $this->assertEquals(200, $gotStats->getResponse()->getStatusCode());
        $this->assertEquals(Server::$url, (string) $gotStats->getEffectiveUri());
        $this->assertEquals(Server::$url, (string) $gotStats->getRequest()->getUri());
        $this->assertGreaterThan(0, $gotStats->getTransferTime());
    }