@Test
public void testLastUpdate() {

    item.setState(new DecimalType(2005));
    ZonedDateTime lastUpdate = PersistenceExtensions.lastUpdate(item, TestPersistenceService.ID);
    assertNotNull(lastUpdate);
    assertEquals(ZonedDateTime.of(2012, 1, 1, 0, 0, 0, 0, ZoneId.systemDefault()), lastUpdate);
    // default persistence service
    lastUpdate = PersistenceExtensions.lastUpdate(item);
    assertNull(lastUpdate);
}