bundle2: make it possible to declare params handled by a part handler...
bundle2: make it possible to declare params handled by a part handler
If we are to enforce the mandatory aspect of parameter, we need a way to
discover what a handler supports. The best option we end up with is this a simple
declaration of known parameters at registration time.
We simply plug the list of parameters on the function object because Python lets
us do that and there is no benefit for a more complicated way.
One of the handlers is updated for example and testing.