Bug 336225 Trim bars do not get unrendered by the rendering engine when trimmed window is unrendered
The trim bars are "ignored" by the rendering engine as it does not perform an unrendering pass on them when the parent trimmed window is being unrendered.
tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/workbench/PartRenderingEngineTests.java
MPart partB = BasicFactoryImpl.eINSTANCE.createPart();
		partB.setElementId("partB");
		partB.setContributionURI("platform:/plugin/org.eclipse.e4.ui.tests/org.eclipse.e4.ui.tests.workbench.SampleView");
		MPart partC = BasicFactoryImpl.eINSTANCE.createPart();
		partC.setElementId("partC");
		partC.setContributionURI("platform:/plugin/org.eclipse.e4.ui.tests/org.eclipse.e4.ui.tests.workbench.SampleView");
		container.getChildren().add(partA);
		container.getChildren().add(partB);
		container.getChildren().add(partC);
		wb = new E4Workbench(application, appContext);
		wb.createAndRunUI(window);
		
		
		container.setSelectedElement(partA);
		partB.setToBeRendered(false);
		assertTrue(
				"Changing the TBR of a non-selected element should not change the value of the container's seletedElement",
				container.getSelectedElement() == partA);
		
		
		container.setSelectedElement(partA);
		partA.setToBeRendered(false);
		assertTrue(
				"Changing the TBR of the selected element should have set the field to null",
				container.getSelectedElement() == null);
	}
	public void testSelectedElementNullingParentChange() {
		MApplication application = ApplicationFactoryImpl.eINSTANCE
				.createApplication();
		application.setContext(appContext);