How to write an own resize corner/handle for an NSWindow?

How can I write an own resize corner/handle for an NSWindow? I'm using a subclass of 开发者_如何学Goan NSWindow without the default resize corner, but I need it for my window.

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The basic outline:

• Create a view.
• Put some "drag me" indicator appropriate to your window in the view.
• Have the view's drag action method respond by resizing the window so that the corner in question is now located at the current mouse position.