Bug 319011 NPE when closing editor after closing a perspective
bundles/org.eclipse.e4.ui.workbench.swt/src/org/eclipse/e4/ui/internal/workbench/swt/PartRenderingEngine.java
renderer.postProcess(element);
			
			if (element.getParent() instanceof MUIElement) {
				MElementContainer<MUIElement> parentElement = element
						.getParent();
				AbstractPartRenderer parentRenderer = getRendererFor(parentElement);
				if (parentRenderer != null)
					parentRenderer.childRendered(parentElement, element);
			}
		} else {
			
			if (element instanceof MContext) {
				MContext ctxt = (MContext) element;
				IEclipseContext lclContext = ctxt.getContext();
				if (lclContext instanceof IDisposable) {
					((IDisposable) lclContext).dispose();
				}
			}
		}
		return newWidget;
	}
	private IEclipseContext getContext(MElementContainer<MUIElement> parent) {
		if (parent instanceof MContext) {
			return ((MContext) parent).getContext();
		}
		return modelService.getContainingContext(parent);
	}
	public Object createGui(MUIElement element) {
		
		Object parent = null;