Bug 323389 Prompt required when resetting perspectives from the perspective switcher
We prompt in 3.x, so we should prompt in 4.x.
bundles/org.eclipse.e4.ui.workbench.addons.swt/src/org/eclipse/e4/ui/workbench/addons/perspectiveswitcher/PerspectiveSwitcher.java
return;
			MWindow perspWin = modelService.getTopLevelWindowFor((MUIElement) changedObj);
			MWindow switcherWin = modelService.getTopLevelWindowFor(psME);
			if (perspWin != switcherWin)
				return;
			if (UIEvents.EventTypes.ADD.equals(eventType)) {
				MPerspective added = (MPerspective) event.getProperty(UIEvents.EventTags.NEW_VALUE);
				
				if (!added.isToBeRendered())
					return;
				addPerspectiveItem(added);
			} else if (UIEvents.EventTypes.REMOVE.equals(eventType)) {
				MPerspective removed = (MPerspective) event
						.getProperty(UIEvents.EventTags.OLD_VALUE);
				
				if (!removed.isToBeRendered())
					return;
				removePerspectiveItem(removed);
			}
		}
	};
	@PostConstruct
	void init(IEclipseContext context) {
		eventBroker.subscribe(UIEvents.buildTopic(UIEvents.ElementContainer.TOPIC,
				UIEvents.ElementContainer.CHILDREN), childrenHandler);
		eventBroker.subscribe(
				UIEvents.buildTopic(UIEvents.UIElement.TOPIC, UIEvents.UIElement.TOBERENDERED),
				toBeRenderedHandler);
		eventBroker.subscribe(UIEvents.buildTopic(UIEvents.ElementContainer.TOPIC,
				UIEvents.ElementContainer.SELECTEDELEMENT), selectionHandler);