Last week, we had the author of TDD for a Shopping Website LiveProject. Friday at 11am Ranch time, Steven Solomon will be hosting a live TDD session just for us. See for the agenda and registration link
there is simply no concept like a "global super interface" I think the reason is simply because it wouldn't make much sense to define an abstract global interface all classes must implement. With "Object" that's another thing because it doesn't only provide an abstract interface but instead "real" functionality which is required for all objects in Java to work properly with core concepts and APIs. I hope this makes it clearer.