private function exceptionHtml(\Exception $e)
    {
        $response = new Response();
        $html = $this->render("OwsProxy3CoreBundle::exception.html.twig", array("exception" => $e));
        $response->headers->set('Content-Type', 'text/html');
        $response->setStatusCode($e->getCode() ?: 500);
        $response->setContent($html->getContent());
        return $response;
    }