--- 
+++ 
@@ -27,7 +27,7 @@
      */
     public MultiplePiePlot(CategoryDataset dataset) {
         super();
-        this.dataset = dataset;
+this.setDataset(dataset);
         PiePlot piePlot = new PiePlot(null);
         this.pieChart = new JFreeChart(piePlot);
         this.pieChart.removeLegend();