public void testSerialization() {

        RingPlot p1 = new RingPlot(null);
        GradientPaint gp = new GradientPaint(1.0f, 2.0f, Color.yellow,
                3.0f, 4.0f, Color.red);
        p1.setSeparatorPaint(gp);
        RingPlot p2 = null;
        try {
            ByteArrayOutputStream buffer = new ByteArrayOutputStream();
            ObjectOutput out = new ObjectOutputStream(buffer);
            out.writeObject(p1);
            out.close();

            ObjectInput in = new ObjectInputStream(
                    new ByteArrayInputStream(buffer.toByteArray()));
            p2 = (RingPlot) in.readObject();
            in.close();
        }
        catch (Exception e) {
            e.printStackTrace();
        }
        assertEquals(p1, p2);