[dancer-users] How to keep Dancer2::Session::Cookie after browser session ends?

Hi! I use Dancer2::Session::Cookie and am trying to implement "Remember me" option for user login. I understand that I need to set 'expires' to some future date for session cookie, but how do I do it in Dancer? 'cookie_duration' configuration parameter makes this, but it is read-only and I can not change it depending on user input.