public void testSerialization() {
        PiePlot p1 = new PiePlot(null);
        PiePlot 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 = (PiePlot) in.readObject();
            in.close();
        }
        catch (Exception e) {
            e.printStackTrace();
        }
        assertEquals(p1, p2);