@Test
public void testToJson() {

    LOG.info("testToJson");
    Assert.assertEquals(
            "{\"time\":@DATETIME,\"position\":{\"lat\":1.0,\"lon\":2.0}}",
            TestUtils.replaceUniques(x.toJson()));
    Assert.assertEquals(
            "{\"time\":@DATETIME,\"position\":{\"lat\":-1.0,\"lon\":-2.0}}",
            TestUtils.replaceUniques(y.toJson()));
}