protected function createContent($type)
    {
        if ($type == 'json') {
            $this->headers['content_type'] = 'application/json; charset=UTF-8';

            return json_encode(['url' => $this->ch, 'status' => 'ok']);
        } elseif ($type == 'xml') {
            $this->headers['content_type'] = 'text/xml; charset=UTF-8';

            return '<?xml version="1.0" encoding="UTF-8"?><result><url>'.$this->ch.'</url><status>ok</status></result>';
        }

        return 'ok';
    }