    def _setcookie(self, session_id, expires='', **kw):
        cookie_name = self._config.cookie_name
        cookie_domain = self._config.cookie_domain
        cookie_path = self._config.cookie_path
        httponly = self._config.httponly
        secure = self._config.secure
        web.setcookie(cookie_name, session_id, expires=expires, domain=cookie_domain, httponly=httponly, secure=secure, path=cookie_path)