Bug 290964 Factor out model loading from Workbench so that it is plugable
We want to support different workbench restoreing possibilities and for this we need to delegate the loading to an external instance
bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/workbench/ui/internal/Workbench.java
public void closeWindow(MWindow workbenchWindow) {
		windowHandler.close(workbenchWindow.getWidget());
	}
	public Object getWindow() {
		return workbench.getChildren().get(0).getWidget();
	}
	/*
	 * For use when there is no real styling engine present. Has no behaviour but conforms to
	 * IStylingEngine API.
	 * 
	 * @param appContext
	 */
	private static void initializeNullStyling(IEclipseContext appContext) {
		appContext.set(IStylingEngine.SERVICE_NAME, new IStylingEngine() {
			public void setClassname(Object widget, String classname) {
			}
			public void setId(Object widget, String id) {
			}
			public void style(Object widget) {
			}
		});
	}
	public MApplication getModel() {
		return workbench;
	}
}