Thank you!

In anticipation for future tax changes I would probably have an abstract function that can take the tax as a parameter directly while being called, if it gets a value it uses it, otherwise it uses the default ones. Not 100% sure if the term is abstract function or it's named differently, I remember reading about these somewhere at one point. Or maybe the term is overloaded, I guess we might see this in one of @kouba01's lessons.