I havesome concerns about the game of whack-a-mole here, we clearly do not do this validation on most of theset_* methods.

But, adding to all would be a much larger task, and has performance considerations as well. And this one has proven to be problematic, in at least one instance, so not too upset at adding it here.

If it weren't forArtist.set() and**kwargs on__init__ expanding toset_* methods, I'd argue that this job is actually pretty well handled by type checking... But those are two pretty massive holes (as well as, of course, type checking being optional).