[woadwarrior01]

This is very reminiscent of zope.interface used in Twisted. I wouldn't want to argue for or against it, but I've had times when something like this might have been useful in large code bases.

[1]: http://docs.zope.org/zope.interface/ [2]: http://twistedmatrix.com/documents/14.0.0/core/howto/compone...