Bug 299435 NPE closing contacts demo with a dirty part
bundles/org.eclipse.e4.ui.workbench.renderers.swt/src/org/eclipse/e4/workbench/ui/renderers/swt/WBWRenderer.java
if (!boundsJob.windowsToUpdate.contains(windowModel))
							boundsJob.windowsToUpdate.add(windowModel);
					}
				}
			}
		};
		eventBroker.subscribe(UIEvents.buildTopic(UIEvents.Window.TOPIC),
				sizeHandler);
	}
	@PreDestroy
	public void contextDisposed() {
		eventBroker.unsubscribe(shellUpdater);
		eventBroker.unsubscribe(visibilityHandler);
		eventBroker.unsubscribe(sizeHandler);
	}
	public Object createWidget(MUIElement element, Object parent) {
		final Widget newWidget;
		if (!(element instanceof MWindow)
				|| (parent != null && !(parent instanceof Shell)))
			return null;
		MWindow wbwModel = (MWindow) element;
		Shell parentShell = (Shell) parent;
		IEclipseContext parentContext = getContextForParent(element);
		Shell wbwShell;
		if (parentShell == null) {
			wbwShell = new Shell(Display.getCurrent(), SWT.SHELL_TRIM);
		} else {
			wbwShell = new Shell(parentShell, SWT.SHELL_TRIM);
		}
		wbwShell.setBounds(wbwModel.getX(), wbwModel.getY(), wbwModel