and nothing is true until I call `to_s`, right?
why can't i say 
```ruby
cc = CC.new({})
cc[:max_age] = 3600
cc.to_s
```
and to_s reproduces a different value every time i change state inside CC. why shouldn't I be able to update any directive I want and get a different representation from `to_s` ? if it shouldn't be able to do that, the API shouldn't let me, but it does, at the moment.