How about keeping this method, and have it raise a @addr is not set exception, and remove the two not_nil! assertions above? I'm guessing it would be more descriptive should we land in that case.

I'm not sure. Either @addr4 or @addr6 must have been set in #initialize (otherwise it raises). The compiler can't know about it because that depends on the third-party @family variable. Let's avoid an overload for an impossible case?

Sounds reasonable 👍

@ysbaddaden @spalladino Please next time prefer adding a return type annotation here, which makes docs more clear and removes the need to write a typeof test for this, which is redundant

Ok, that's noted!