code: function (forwardToLast) {
          var clipList = this._clipList;
          var animation = this.animation;
          for (var i = 0; i < clipList.length; i++) {
              var clip = clipList[i];
              if (forwardToLast) {
                  // Move to last frame before stop
                  clip.onframe(this._target, 1);
              }
              animation && animation.removeClip(clip);
          }
          clipList.length = 0;
      }
docs: 停止动画
  @param {boolean} forwardToLast If move to last frame before stop