@Test
public void addChangeListener() {

    PropertySource ps = BuildablePropertySource.builder().withName("test").
            withSimpleProperty("foo", "bar").build();
    PropertySourceChangeSupport support = new PropertySourceChangeSupport(ChangeSupport.SUPPORTED, ps);
    support.load(ps.getProperties());
    BiConsumer<Set<String>, PropertySource> l = mock(BiConsumer.class);
    support.addChangeListener(l);
    support.load(Collections.emptyMap());
    verify(l).accept(any(), any());
}