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
public static final int TOOL_BAR_CONTRIBUTION__VISIBLE = UiPackageImpl.ELEMENT_CONTAINER__VISIBLE;
	/**
	 * The feature id for the '<em><b>Parent</b></em>' container reference.
	 * <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * @generated
	 * @ordered
	 */
	public static final int TOOL_BAR_CONTRIBUTION__PARENT = UiPackageImpl.ELEMENT_CONTAINER__PARENT;
	/**
	 * The feature id for the '<em><b>Container Data</b></em>' attribute.
	 * <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * @generated
	 * @ordered
	 */
	public static final int TOOL_BAR_CONTRIBUTION__CONTAINER_DATA = UiPackageImpl.ELEMENT_CONTAINER__CONTAINER_DATA;
	/**
	 * 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 TOOL_BAR_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