Testing why, when, and how of overriding AS3's event.clone() method

Main.as

package
{
	import flash.display.Sprite;
	import flash.events.Event;
	
	public class Main extends Sprite
	{
		private var _child1:Sprite;
		private var _child2:Sprite;
		private var _child3:Sprite;
		
		public function Main()
		{
			_child1 = new Sprite();
			_child1.name = "child1";
			_child1.addEventListener(Event.ADDED_TO_STAGE, onAddedToStage, false, 0, false);
			_child1.addEventListener("Added: child3", onChild3Added, false, 0, true);
			_child2 = new Sprite();
			_child2.name = "child2";
			_child2.addEventListener(Event.ADDED_TO_STAGE, onAddedToStage, false, 0, false);
			_child2.addEventListener("Added: child3", onChild3Added, false, 0, true);
			_child3 = new Sprite();
			_child3.name = "child3";
			_child3.addEventListener(Event.ADDED_TO_STAGE, onAddedToStage, false, 0, false);
			_child3.addEventListener("Added: child3", onChild3Added, false, 0, true);
			_child2.addChild(_child3);
			_child1.addChild(_child2);
			addChild(_child1);
		}
		
		protected function onChild3Added(event:Event):void
		{
			trace("child 3 added - target = " + event.target.name);
			trace("\tcurrent target = " + event.currentTarget.name);
			switch(event.currentTarget){
				case _child3:
					_child2.dispatchEvent(event);
					break;
				case _child2:
					_child1.dispatchEvent(event);
					break;
			}
		}
		
		protected function onAddedToStage(event:Event):void
		{
			event.target.dispatchEvent(new TestEvent("Added: " + event.target.name, false));
			event.target.dispatchEvent(new TestEvent("Added: " + event.target.name, false, false));
		}
	}
}

TestEvent.as

package
{
	import flash.events.Event;
	
	public class TestEvent extends Event
	{
		private var _cloneWithThis:Boolean;
		
		public function TestEvent(type:String, bubbles:Boolean=false, cloneWithThis:Boolean = true)
		{
			super(type, bubbles, cancelable);
			_cloneWithThis = cloneWithThis;
		}
		
		override public function clone():Event {
			trace("cloning: " + type);
			trace("\twith this? " + _cloneWithThis);
			if(_cloneWithThis)
				return this;
			else
				return new TestEvent(type, bubbles, false);
		}
	}
}