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
if (eNotificationRequired())
			eNotify(new ENotificationImpl(this, Notification.SET, MenuPackageImpl.HANDLED_ITEM__WB_COMMAND, oldWbCommand, wbCommand));
	}
	/**
	 * <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * @generated
	 */
	public List<MParameter> getParameters() {
		if (parameters == null) {
			parameters = new EObjectContainmentEList<MParameter>(MParameter.class, this, MenuPackageImpl.HANDLED_ITEM__PARAMETERS);
		}
		return parameters;
	}
	/**
	 * <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * @generated
	 */
	@Override
	public NotificationChain eInverseRemove(InternalEObject otherEnd, int featureID, NotificationChain msgs) {
		switch (featureID) {
			case MenuPackageImpl.HANDLED_ITEM__PARAMETERS:
				return ((InternalEList<?>)getParameters()).basicRemove(otherEnd, msgs);
		}
		return super.eInverseRemove(otherEnd, featureID, msgs);
	}
	/**
	 * <!-- begin-user-doc -->
	 * <!-- end-user-doc -->