code: public function showAction(Request $request, Application $app)
      {
          $options = array(
              'twig' => $app["twig"],
              'template_assets' => $app["red_kite_cms.template_assets"],
              "configuration_handler" => $app["red_kite_cms.configuration_handler"],
              "plugin_manager" => $app["red_kite_cms.plugin_manager"],
          );
  
          return parent::show($options);
      }
docs: Show themes panel action
  
  @param \Symfony\Component\HttpFoundation\Request $request
  @param \Silex\Application                        $app
  @return \Symfony\Component\HttpFoundation\Response