Elgg\Http\ResponseFactoryTest::testSendsReponseOnlyOnce PHP Method

    public function testSendsReponseOnlyOnce()
    {
        $service = $this->createService();
        ob_start();
        $response = $service->prepareResponse('foo');
        $sent_response = $service->send($response);
        $this->assertInstanceOf(Response::class, $sent_response);
        $this->assertEquals($sent_response, $service->send($response));
        $output = ob_get_clean();
        $this->assertEquals('foo', $output);
    }