But what's more surprising is that -respondsToSelector doesn't work
as expected when sent to super.
This does not tell you whether your superclass responds to a selector.
It calls the superclass's _implementation_ of -respondsToSelector:.
Which is the same as calling [self respondsToSelector:], unless your
class overrides -respondsToSelector: itself.
"super" calls are a slippery concept, but this isn't a bug in -
respondsToSelector: or an Obj-C issue. People have been getting
confused about this in dynamic OO languages all the way back to
Smalltalk-72 :)
