anchor.diff:      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}}});
  +    pieByLevelChart.draw(table, {'series': {'labels': {'enabled': true}}});
       pieSize++;
  -    chart.resize();
  +    pieByLevelChart.resize();
       pieSize--;
  -    chart.resize();
  +    pieByLevelChart.resize();
     }
   }
  
positive.code:   @observable num pieSize = 500;
  
    Layout layout;
  
    PageStats.created() : super.created();
  
    ready() {
  
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);
  