Bug 326175 WBWRenderer arbitrarily modifies the window's parent's active context chain
The window's parent's context arbitrarily changes its active child to the window being rendered in createWidget(*).
tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/workbench/PartRenderingEngineTests.java
wb.createAndRunUI(window);
		IPresentationEngine engine = appContext.get(IPresentationEngine.class);
		engine.createGui(window2);
		
		
		
		EPartService service = (EPartService) window2.getContext().get(
				EPartService.class.getName());
		service.showPart("part", EPartService.PartState.VISIBLE);
		service.showPart("part", EPartService.PartState.CREATE);
		service.showPart("part2", EPartService.PartState.CREATE);
		while (Display.getDefault().readAndDispatch())
			;
	}
	public void testPart_ToBeRendered() {
		MApplication application = ApplicationFactoryImpl.eINSTANCE
				.createApplication();
		application.setContext(appContext);
		appContext.set(MApplication.class.getName(), application);
		MWindow window = BasicFactoryImpl.eINSTANCE.createWindow();
		application.getChildren().add(window);
		MPartStack stack = BasicFactoryImpl.eINSTANCE.createPartStack();
		window.getChildren().add(stack);
		MPart partA = BasicFactoryImpl.eINSTANCE.createPart();
		partA.setElementId("partA");
		partA.setContributionURI("platform:/plugin/org.eclipse.e4.ui.tests/org.eclipse.e4.ui.tests.workbench.SampleView");
		MPart partB = BasicFactoryImpl.eINSTANCE.createPart();
		partB.setElementId("partB");
		partB.setContributionURI("platform:/plugin/org.eclipse.e4.ui.tests/org.eclipse.e4.ui.tests.workbench.SampleView");
		stack.getChildren().add(partA);