### Question:
PropertiesPanelNotifier { void onCanvasSelectionEvent(final @Observes CanvasSelectionEvent event) { final Collection<String> identifiers = event.getIdentifiers(); if (identifiers.size() > 0) { setSelectedElementUUID(identifiers.iterator().next()); } } @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 testOnCanvasSelectionEvent() { final CanvasSelectionEvent selectionEvent = mock(CanvasSelectionEvent.class); final String uuid1 = "uuid1"; final String uuid2 = "uuid2"; final List<String> t = asList(uuid1, uuid2); when(selectionEvent.getIdentifiers()).thenReturn(t); notifier.onCanvasSelectionEvent(selectionEvent); verify(notifier).setSelectedElementUUID(uuid1); }