methodclosure object is not cleaned from memory

MethodClosureTest.as

package {
	import flash.display.Sprite;
	import flash.events.Event;
	import flash.utils.getTimer;

	public class MethodClosureTest extends Sprite {
		public function MethodClosureTest() {
			addEventListener(Event.ENTER_FRAME, onEnterFrame);
		}

		private function onEnterFrame(event:Event):void {
			var func:Function = function ():void {
				var time:Number = getTimer();
				trace("here: "+time);
			};
			func();
		}
	}
}