XYSeries series1 = createSeries1();
XYSeries series2 = createSeries2();
DefaultTableXYDataset dataset = new DefaultTableXYDataset();
dataset.addSeries(series1);
dataset.addSeries(series2);
// Test that there are 6 X points and some specific values
assertEquals(6, dataset.getItemCount());
assertEquals(6, dataset.getX(0, 5).intValue());
assertEquals(null, dataset.getY(0, 5));