Looks good to me, Samuel.  I have implemented that stupid method,
exactly as you describe, in many different subclasses at this point.

The main awkward thing is that it calls respondsTo:, which I find a
little icky even though others seem to like it just fine.  I would tend
to blame the method itself, though, not the implementation.  Why isn't
the message going to the right object to begin with?

-Lex