public function testRender()
{
$app = $this->app;
$parameters = array('error_title' => 'error', 'error_message' => 'error');
$response = $app->render('error.twig', $parameters);
$this->assertEquals('Symfony\\Component\\HttpFoundation\\Response', get_class($response));
$this->assertStringStartsWith('<!doctype html>', $response->getContent());
}