code: public function restart($date = false)
      {
          $this->cookie_jar->restartSession($date);
          $this->authenticator->restartSession();
          $this->http_referer = null;
      }
docs: Removes expired and temporary cookies as if the browser was closed and re-opened.
  Authorisation has to be obtained again as well.
  
  @param string/integer $date   Time when session restarted. If omitted then all persistent
  cookies are kept.