as3 阻止后续侦听器

public class Test1 extends Sprite
    {
        private var spr:Sprite;
        private var spr2:Sprite;
        public function Test1()
        {
            spr = new Sprite();
            spr.graphics.beginFill(0xff0000,1);
            spr.graphics.drawCircle(100,100,10);
            spr.graphics.endFill();
            this.addChild(spr);
            spr.addEventListener(MouseEvent.CLICK,_hander);
            spr.addEventListener(MouseEvent.CLICK,_hander);
            spr.addEventListener(MouseEvent.CLICK,_hander);
            spr.addEventListener(MouseEvent.CLICK,_hander);
            
            spr2 = new Sprite();
            spr2.graphics.beginFill(0xff0000,1);
            spr2.graphics.drawCircle(200,100,10);
            spr2.graphics.endFill();
            this.addChild(spr2);
            spr2.addEventListener(MouseEvent.CLICK,_hander2);
        }
        private function _hander(evt:MouseEvent):void
        {
            trace("click");
        }
        private function _hander2(evt:MouseEvent):void
        {
            trace("click2");
            spr.removeEventListener(MouseEvent.CLICK,_hander);
            //spr一的侦听器函数不触发了
        }
    }

    public class Test1 extends Sprite
    {
        private var spr:Sprite;
        private var spr2:Sprite;
        public function Test1()
        {
            spr = new Sprite();
            spr.graphics.beginFill(0xff0000,1);
            spr.graphics.drawCircle(100,100,10);
            spr.graphics.endFill();
            this.addChild(spr);
            spr.addEventListener(MouseEvent.CLICK,_hander);
            spr.addEventListener(MouseEvent.CLICK,_hander);
            
            spr2 = new Sprite();
            spr2.graphics.beginFill(0xff0000,1);
            spr2.graphics.drawCircle(200,100,10);
            spr2.graphics.endFill();
            this.addChild(spr2);
            spr2.addEventListener(MouseEvent.CLICK,_hander2);
            
            this.stage.addEventListener(MouseEvent.CLICK,_stageClick);
        }
        private function _hander(evt:MouseEvent):void
        {
            trace("click");
            //舞台将不会收到click事件
            evt.stopImmediatePropagation();
        }
        private function _hander2(evt:MouseEvent):void
        {
            trace("click2");
            //spr.removeEventListener(MouseEvent.CLICK,_hander);
            //spr一的侦听器函数不触发了
        }
        private function _stageClick(evt:MouseEvent):void
        {
            trace("stage_click");
        }
    }