Bug 283194 [UI] StackModelFactory does not need 'engine' local
We can remove this from createWidget() final IStylingEngine engine = (IStylingEngine) folderContext .get(IStylingEngine.SERVICE_NAME); because the engine is now passed in via DI. Replace the refs to "engine" with the local "stylingEngine".
bundles/org.eclipse.e4.ui.workbench.renderers.swt/src/org/eclipse/e4/workbench/ui/renderers/swt/StackRenderer.java
CTabItem selItem = findItemForPart(part, selPart);
		if (selItem != null) {
			ctf.setSelection(selItem);
		}
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.e4.workbench.ui.renderers.swt.LazyStackFactory#internalChildAdded
	 * (org.eclipse.e4.ui.model.application.MPart,
	 * org.eclipse.e4.ui.model.application.MPart)
	 */
	@Override
	protected void internalChildAdded(MPart parentElement, MPart element) {
		
		super.internalChildAdded(parentElement, element);
		MItemPart<?> itemPart = (MItemPart<?>) element;
		CTabFolder ctf = (CTabFolder) parentElement.getWidget();
		int createFlags = 0;
		
		
		CTabItem cti = findItemForPart(parentElement, element);
		if (cti == null) {
			int index = calcIndexFor(element);
			
			
			cti = new ETabItem((ETabFolder) ctf, createFlags, index);