Well, the original reason I wanted depend_on was because the constructor of the depender expected certain properties of the database.

If you never call `.save()` on the depended, then it doesn't actually meet my needs.

I agree that it's weird -- although I actually think it's weirder that we *don't* save relationship dependencies. That means that different methods of using SQLalchemy will interact differently with relationship dependencies. Unfortunately, it completely breaks our API test cases if we try to save relationship dependencies because a lot of them turn out to violate key constraints (another bad part about not saving -- constraints aren't evaluated), so I didn't change that part.