### Question:
PropertiesPanelNotifier { void onDomainObjectSelectionEvent(final @Observes DomainObjectSelectionEvent event) { setSelectedElementUUID(event.getDomainObject().getDomainObjectUUID()); } @Inject  PropertiesPanelNotifier(final Event<RefreshFormPropertiesEvent> refreshFormPropertiesEvent,
                                   final SessionManager sessionManager); PropertiesPanelNotifier withOldLocalPart(final String oldLocalPart); PropertiesPanelNotifier withNewQName(final QName newQName); void notifyPanel();  }### Answer:
@Test public void testOnDomainObjectSelectionEvent() { final DomainObjectSelectionEvent selectionEvent = mock(DomainObjectSelectionEvent.class); final DomainObject domainObject = mock(DomainObject.class); final String uuid = "uuid"; when(selectionEvent.getDomainObject()).thenReturn(domainObject); when(domainObject.getDomainObjectUUID()).thenReturn(uuid); notifier.onDomainObjectSelectionEvent(selectionEvent); verify(notifier).setSelectedElementUUID(uuid); }