With What does Apple Swizzle the IsA-pointer in KVO?

FROM : Philip Mötteli
DATE : Fri Nov 23 14:42:35 2007

Hi,


Apple says, that it uses IsA-swizzling as the underlying technology to 
implement KVO.
What are/is the class(es), which replace the original class of the 
observed object? Is it an NSProxy subclass? Different NSProxy 
subclasses, depending on the observed object? Is it a direct subclass 
of the observed object?


Thanks
Phil