anchor.diff:    @observable num pieSize = 500;
   
     Layout layout;
  -
  +  PieChart pieByLevelChart;
  +  
  +  
     PageStats.created() : super.created();
   
     ready() {
  
positive.code:     data.add(["Dartisans", "Level"]);
      dartisansByLevel.keys.forEach((level) => data.add([level, dartisansByLevel[level]]));
      var table = new DataTable(data);
      var chart = new PieChart($["pieByLevel"]);
      chart.draw(table, {'series': {'labels': {'enabled': true}}});
      pieSize++;
      chart.resize();
      pieSize--;
      chart.resize();
    }
  }
  
negative.code: 
    void _setAttributes() {
      layout = $["layout"] as Layout;
      pieByLevelChart = new PieChart($["pieByLevel"]);
      LayoutModel layoutModel = new LayoutModel();
      PageModel model = new PageModel(name: NAME, layoutModel: layoutModel);
      this.init(model);
  