[Python-3000] Generic function PEP won't make it in time

[Talin]

Guido van Rossum wrote:
> Yeah. I like @abstractmethod to mean "not implemented" (except perhaps
> as an end point for cooperative super calls). For the latter concept,
> I propose that all methods present in an apparent ABC are considered
> part of the interface, unless their name starts with a single
> underscore (the latter should be considered implementation details, or
> perhaps definitional details).

I kind of wish that it was called "incomplete" rather than abstract, for 
reasons that we've already discussed.

-- Talin