public function replaceMarkup(FilterResponseEvent $event)
    {
        $request = $event->getRequest();
        $response = $event->getResponse();
        $format = $request->getRequestFormat();
        $content = $response->getContent();

        if (!$content || !array_key_exists($format, $this->markupParser)) {
            return;
        }

        $response->setContent(
            $this->markupParser[$format]->parse($content, $request->getLocale())
        );
    }