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/MenuPackageImpl.java
* The feature id for the '<em><b>Cur Shared Ref</b></em>' reference.
	 * <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * @generated
	 * @ordered
	 */
	public static final int TRIM_CONTRIBUTION__CUR_SHARED_REF = UiPackageImpl.ELEMENT_CONTAINER__CUR_SHARED_REF;
	/**
	 * The feature id for the '<em><b>Visible When</b></em>' containment reference.
	 * <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * @generated
	 * @ordered
	 */
	public static final int TRIM_CONTRIBUTION__VISIBLE_WHEN = UiPackageImpl.ELEMENT_CONTAINER__VISIBLE_WHEN;
	/**
	 * The feature id for the '<em><b>Children</b></em>' containment reference list.
	 * <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * @generated
	 * @ordered
	 */
	public static final int TRIM_CONTRIBUTION__CHILDREN = UiPackageImpl.ELEMENT_CONTAINER__CHILDREN;
	/**
	 * The feature id for the '<em><b>Selected Element</b></em>' reference.
	 * <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * @generated
	 * @ordered
	 */