objective c - Should NSWindowController always be the superclass of a window controller? -

When reading Apple's Cocoa Tutorial, the window controller is just a regular class and assuming that it's perfectly fine, I think this sub-class is better for NSWindowController?

If I get this right, then NSWindowController is a feature class that already has the functionality required by the Window Controller implemented, right?

Will you not use this category, there is a reason for this?

NSObject If I really did not need additional functionality of NSWindowController