[Python-3000] Abilities / Interfaces

[Bill Janssen]

> > Andrew Koenig writes:
> > > For example, I can imagine a single interface having multiple
> > > abilities.
> 
> > Perhaps because it inherits from multiple sub-interfaces?
> 
> Or perhaps because after the interface was defined, someone noticed that it
> happened to have those abilities and wanted to be able to say to after the
> fact.

More of a tagging approach, then?

Something like

  class MyNewClass (ExistingClass, OtherInterfaceIJustNoticedExistingClassImplements):
    pass

?

Bill