private function create404(Http\Request $request, Http\Response $response)
{
$response = $response->withStatus(404);
$originalRequest = $request->getOriginalRequest();
$uri = $originalRequest->getUri();
$escaper = new Escaper();
$message = sprintf("Cannot %s %s\n", $escaper->escapeHtml($request->getMethod()), $escaper->escapeHtml((string) $uri));
return $response->end($message);
}