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
StringBuilder builder = new StringBuilder(element.getClass()
				.getSimpleName());
		String elementId = element.getElementId();
		if (elementId != null && elementId.length() != 0) {
			builder.append(" (").append(elementId).append(") ");
		}
		builder.append("Context");
		return builder.toString();
	}
	public Object createGui(MUIElement element, Object parentWidget,
			IEclipseContext parentContext) {
		if (!element.isToBeRendered())
			return null;
		if (element.getWidget() != null) {
			if (element.getWidget() instanceof Control
					&& parentWidget instanceof Composite) {
				Control ctrl = (Control) element.getWidget();
				if (ctrl.getParent() != parentWidget) {
					ctrl.setParent((Composite) parentWidget);
				}
			}
			return element.getWidget();
		}
		if (element instanceof MContext) {
			MContext ctxt = (MContext) element;
			
			
			if (ctxt.getContext() == null) {
				IEclipseContext lclContext = parentContext
						.createChild(getContextName(element));