tweener test | recursive call

/**
 * Copyright gonoverdrive ( http://wonderfl.net/user/gonoverdrive )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/nfwY
 */

package {
    import flash.display.Sprite;
    import caurina.transitions.Tweener;
    
    public class FlashTest extends Sprite {
        private var cast:Sprite;
        private var w:Number;
        private var h:Number;
        private const WIDTH:Number = 20;
        private const HEIGHT:Number = 20;
        public function FlashTest() {
            w = stage.stageWidth - WIDTH;
            h = stage.stageHeight - HEIGHT;
            cast = new Sprite;
            cast.graphics.beginFill(0x000000);
            cast.graphics.drawRect(0, 0, WIDTH, HEIGHT);
            cast.graphics.endFill();
            addChild(cast);
            
            move();
        }
        
        private function move():void {
            Tweener.addTween(cast, {
                time: 1,
                delay: 3,
                transition: "easeInOutBack",
                x: getRandom(w),
                y: getRandom(h),
                onComplete: function():void {
                    move();
                }
            });   
        }
        
        private function getRandom(_r:Number):int {
            return Math.floor(Math.random() * _r);    
        }
    }
}