public function preView($output) {
        /** @var $purifierConfig \HTMLPurifier_Config */
        $purifierConfig = \HTMLPurifier_Config::createDefault();
        $purifierConfig->set('Core.Encoding', 'UTF-8');
        $purifierConfig->set('HTML.TidyLevel', 'medium');

        /** @var \HTMLPurifier_Config $purifierConfig */
        $purifier = new \HTMLPurifier($purifierConfig);
        $output   = $purifier->purify($output);

        return $output;
    }