removeEventListener() for an anonymous function

I have an event listener with an anonymous function literal, rather than a function reference. What I am trying to figure out is how to remove that event listener.

Obviously, I need a reference to the anonymous function, so the two functions are ===. But, something is going wrong… it just doesn’t work, ad this situation doesn’t generate any feedback to tell me what might be wrong.

There is some good info here, but not a clear explanation.

private static var _myFunc:Function;

public static function addCreditsToolTip(clip:DisplayObject):void
    _myFunc = function():void

    trace(_myFunc); //"function Function() {}" < PERFECT!
    clip.removeEventListener("rollOver", _myFunc); // < this doesn't work.