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/src/org/eclipse/e4/ui/model/application/ui/menu/impl/MenuFactoryImpl.java
public MToolBarContributions createToolBarContributions() {
		ToolBarContributionsImpl toolBarContributions = new ToolBarContributionsImpl();
		return toolBarContributions;
	}
	/**
	 * <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * @generated
	 */
	public MTrimContribution createTrimContribution() {
		TrimContributionImpl trimContribution = new TrimContributionImpl();
		return trimContribution;
	}
	/**
	 * <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * @generated
	 */
	public MTrimContributions createTrimContributions() {
		TrimContributionsImpl trimContributions = new TrimContributionsImpl();
		return trimContributions;
	}
	/**
	 * <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * @generated
	 */
	public ItemType createItemTypeFromString(EDataType eDataType, String initialValue) {
		ItemType result = ItemType.get(initialValue);
		if (result == null) throw new IllegalArgumentException("The value '" + initialValue + "' is not a valid enumerator of '" + eDataType.getName() + "'");