Bug 317405 [Model] HandledItem should be abstract
Looks like an oversight the only real types are HandledMenuItem and HandledToolItem.
bundles/org.eclipse.e4.ui.model.workbench.edit/src/org/eclipse/e4/ui/model/application/ui/advanced/provider/PerspectiveStackItemProvider.java
MBasicFactory.INSTANCE.createPartSashContainer()));
		newChildDescriptors.add
			(createChildParameter
				(UiPackageImpl.Literals.ELEMENT_CONTAINER__CHILDREN,
				 MBasicFactory.INSTANCE.createWindow()));
		newChildDescriptors.add
			(createChildParameter
				(UiPackageImpl.Literals.ELEMENT_CONTAINER__CHILDREN,
				 MBasicFactory.INSTANCE.createTrimmedWindow()));
		newChildDescriptors.add
			(createChildParameter
				(UiPackageImpl.Literals.ELEMENT_CONTAINER__CHILDREN,
				 MBasicFactory.INSTANCE.createTrimBar()));
		newChildDescriptors.add
			(createChildParameter
				(UiPackageImpl.Literals.ELEMENT_CONTAINER__CHILDREN,
				 MBasicFactory.INSTANCE.createStackElement()));
	}
	/**
	 * Return the resource locator for this item provider's resources.
	 * <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * @generated
	 */
	@Override
	public ResourceLocator getResourceLocator() {
		return UIElementsEditPlugin.INSTANCE;
	}
}