public DefaultIntervalXYDataset createSampleDataset1() {
        DefaultIntervalXYDataset d = new DefaultIntervalXYDataset();
        double[] x1 = new double[] {1.0, 2.0, 3.0};
        double[] x1Start = new double[] {0.9, 1.9, 2.9};
        double[] x1End = new double[] {1.1, 2.1, 3.1};
        double[] y1 = new double[] {4.0, 5.0, 6.0};
        double[] y1Start = new double[] {1.09, 2.09, 3.09};
        double[] y1End = new double[] {1.11, 2.11, 3.11};
        double[][] data1 = new double[][] {x1, x1Start, x1End, y1, y1Start,
                y1End};
        d.addSeries("S1", data1);

        double[] x2 = new double[] {11.0, 12.0, 13.0};
        double[] x2Start = new double[] {10.9, 11.9, 12.9};
        double[] x2End = new double[] {11.1, 12.1, 13.1};
        double[] y2 = new double[] {14.0, 15.0, 16.0};
        double[] y2Start = new double[] {11.09, 12.09, 13.09};
        double[] y2End = new double[] {11.11, 12.11, 13.11};
        double[][] data2 = new double[][] {x2, x2Start, x2End, y2, y2Start,
                y2End};
        d.addSeries("S2", data2);
        return d;