private function getDefaultPurifier()
    {
        $sanitizer = \HTMLPurifier_Config::createDefault();

        $sanitizer->set('HTML.TargetBlank', true);
        $sanitizer->set('URI.AllowedSchemes', ['http' => true, 'https' => true]);
        $sanitizer->set('AutoFormat.RemoveEmpty', true);
        $sanitizer->set('HTML.DefinitionID', 'html5-definitions');

        if (!is_dir('/tmp/purifier')) {
            mkdir('/tmp/purifier', 0777, true);
        }

        $sanitizer->set('Cache.SerializerPath', '/tmp/purifier');

        return $sanitizer;
    }