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/HandledItemImpl.java
/**
	 * <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * @generated
	 */
	@Override
	protected EClass eStaticClass() {
		return MenuPackageImpl.Literals.HANDLED_ITEM;
	}
	/**
	 * <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * @generated
	 */
	public MCommand getCommand() {
		if (command != null && ((EObject)command).eIsProxy()) {
			InternalEObject oldCommand = (InternalEObject)command;
			command = (MCommand)eResolveProxy(oldCommand);
			if (command != oldCommand) {
				if (eNotificationRequired())
					eNotify(new ENotificationImpl(this, Notification.RESOLVE, MenuPackageImpl.HANDLED_ITEM__COMMAND, oldCommand, command));
			}
		}
		return command;
	}
	/**
	 * <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * @generated
	 */