子弹碰撞到边界需要出现爆炸动画，然后子弹消失，出现爆炸。
    难点是在指定位置出现爆炸点
    这里可以通过重新sprite的锚点来确定爆炸位置。

    1.     TankWar.prototype.removeGun = function () {
    2.       const {gun} = this;
    3.       const getGun = gun.getChildAt(0);
    4.       gun.removeChildren();
    5.       this.boom(getGun.x,getGun.y)
    6.     }
    1.       TankWar.prototype.boom = function (x,y) {
    2.         const {BOOM} = constants;
    3.         const id = this.loader.resources.spaceship.spritesheet.animations;
    4.         console.log(id[BOOM],BOOM)
    5.         const boom = new PIXI.AnimatedSprite(id[BOOM]);
    6.         boom.animationSpeed = 0.2;
    7.         boom.play();
    8.         boom.name= BOOM
    9.         boom.loop = false;
    10.         boom.onComplete = () => {
    11.           const getBOOM = this.application.stage.getChildByName(BOOM);
    12.           this.application.stage.removeChild(getBOOM);         
    13.         }
    14.         boom.scale.x = 2;
    15.         boom.scale.y = 2;
    16.         boom.anchor.set(0.5,0.5);
    17.         boom.x = x;
    18.         boom.y = y;
    19.         this.application.stage.addChild(boom);
    20.       }