Why would you use Character!null

I’m just getting back into :sk: and am going some of my older code. For the parameter for a method, I have:
(Character unit : Character!null)
and I can’t figure out why I would add the Character!null.

It looks like you just wanted the default parameter to be null so that you can call that method with no parameters.

It allows you to do:

That method always takes a Character parameter. Realistically then, I should omit it.