code: function(path) {
                  this.callBase({
                      beginValue: function(target) {
                          this.beginPath = target.getPathData();
                          return 0;
                      },
                      finishValue: 1,
                      setter: function(target, value) {
                          target.setPathData(g.pathTween(this.beginPath, path, value));
                      }
                  });
              }
docs: @constructor
  @for kity.PathAnimator
  
  @grammar new kity.Path.Animator(path)
  
  @param  {String|PathSegment} path 目标形状的路径数据