public function handleInternal(string $path, string $message = null)
    {
        $route = $this->internalRoutes[$path]
            ?? $this->internalRoutes[null]
            ?? null;

        if (!$route) {
            throw new NotFoundException("No internal route to handle: " . $path);
        }

        $this->errorMessage = $message;
        if ($message) {
            $route->setArguments([$message]);
        }

        $route->setMatchedPath($path);
        $this->lastRoute = $route;
        return $route->handle(null, $this->di);
    }