JFreeChart chart1 = new JFreeChart("Title", 
                new Font("SansSerif", Font.PLAIN, 12), new PiePlot(), true);
        JFreeChart chart2 = new JFreeChart("Title", 
                new Font("SansSerif", Font.PLAIN, 12), new PiePlot(), true);
        assertTrue(chart1.equals(chart2));
        assertTrue(chart2.equals(chart1));