React\Tests\HttpClient\RequestTest::successfulAsyncConnectionMock PHP Method

    private function successfulAsyncConnectionMock()
    {
        $deferred = new Deferred();
        $this->connector->expects($this->once())->method('create')->with('www.example.com', 80)->will($this->returnValue($deferred->promise()));
        return function () use($deferred) {
            $deferred->resolve($this->stream);
        };
    }