@Test
public void testToStringJson() {

    LOG.info("testToStringJson");
    final GeoRectangle a = new GeoRectangle(new GeoPoint(1.0, 2.0), new GeoPoint(3.0, 4.0));
    final String x1 = Json.toStringJson(a);
    Assert.assertEquals(
            "{\"southWest\":{\"lat\":1.0,\"lon\":2.0},\"northEast\":{\"lat\":3.0,\"lon\":4.0}}",
            x1);
    Assert.assertEquals("null", Json.toStringJson(null));
}