public void testHashCode() {
        XYPointerAnnotation a1 = new XYPointerAnnotation("Label", 10.0, 20.0,
                Math.PI);
        XYPointerAnnotation a2 = new XYPointerAnnotation("Label", 10.0, 20.0,
                Math.PI);
        assertTrue(a1.equals(a2));
        int h1 = a1.hashCode();
        int h2 = a2.hashCode();
        assertEquals(h1, h2);