@Test
public void testPropertyUpdate() {

    SettableConfig config = new DefaultSettableConfig();
    config.setProperty("a", 1);
    DefaultPropertyFactory factory = new DefaultPropertyFactory(config);
    Iterator<Integer> it = Archaius2Ext.watch(factory, "a", Integer.class).toIterable().iterator();
    assertThat(it.next()).isEqualTo(1);
    config.setProperty("a", 2);
    factory.invalidate();
    assertThat(it.next()).isEqualTo(2);
}