protected function redirect($controller = null, $action = null)
    {
        if (null === $controller) {
            $controller = Application::getInstance()->getDefaultController();
        }
        if (null === $action) {
            $action = Application::getInstance()->getDefaultAction();
        }
        $destination = sprintf("Location: %s%s/%s", $this->request->getContextPrefix(), $controller, $action);
        header($destination);
        exit();
    }