public function testInvokeSubRequestUsesResponseObject()
 {
     $app = new App();
     $app->get('/foo', function ($req, $res) {
         $res->write("foo {$req->getParam('bar')}");
         return $res;
     });
     $resp = new Response(201);
     $newResponse = $subReq = $app->subRequest('GET', '/foo', 'bar=bar', [], [], '', $resp);
     $this->assertEquals('foo bar', (string) $subReq->getBody());
     $this->assertEquals(201, $newResponse->getStatusCode());
 }