Antoine: I don't have any problem with that personally, but Michael did, and he's the maintainer :)

But there is a small advantage: it means you don't have to keep repeating the 'unittest.TestCase' boilerplate in each subclass declaration, you only have to decorate the base class once.

Daniel:  Oops, you are right. Michael seemed to have some idea on how to implement the decorator.  The class attribute was my contribution, and obviously that isn't going to work.  I wanted something more transparent than a magic decorator, but it looks like magic will be required.

Which, IMO, is a point in Antoine's favor.  Let's see what Michael has to say.