[Czarnian]

You're right. The APIs don't need to be implemented, just documented.

I'll go you one further. It's better to work without a functioning API. With stubs and dummies, you can tightly control inputs and test way more effectively. If you're developing against an active api, you add a whole level of complexity that makes it that much harder to debug. I don't know how many hours I've wasted trying to find bugs that turned out to be outside the scope of what I was working on.