How to use the terra-application-layout.Utils.utilityHelpers function in terra-application-layout

title: 'Custom Checkbox Item',
      isSelectable: true,
      isSelected: checkboxItemEnabled,
      isReadOnly: false,
      parentKey: Utils.utilityHelpers.defaultKeys.MENU,
    }, {
      key: 'readonly-item',
      title: 'Custom ReadOnly Item',
      isSelectable: true,
      isReadOnly: true,
      parentKey: Utils.utilityHelpers.defaultKeys.MENU,
    }, {
      key: 'additional-3',
      contentLocation: Utils.utilityHelpers.locations.FOOTER,
      title: 'Custom Footer',
      parentKey: Utils.utilityHelpers.defaultKeys.MENU,
    }];

    /**
     * The data provided for utilityConfig will be visible in the ApplicationLayout's header in the
     * standard rendering mode and within the menus in the compact rendering mode.
     *
     * The ApplicationLayout's Utils export provides a helper function named getDefaultUtilityConfig that will
     * generate the configuration for the standard set of utility options. If the standard configuration is not
     * desirable, an entirely custom configuration can be used instead.
     */
    const utilityConfig = Object.freeze({
      title: 'Swanson, Henry',
      accessory: userAvatar,
      menuItems: Utils.utilityHelpers.getDefaultUtilityItems(intl, userData, customUtilityItems),
      initialSelectedKey: Utils.utilityHelpers.defaultKeys.MENU,
      onChange: (event, itemData, disclose) => {

render() {
    const { intl, location } = this.props;
    const { checkboxItemEnabled } = this.state;

    const customUtilityItems = [{
      key: 'additional-1',
      title: 'Drill-in Item',
      childKeys: [
        'additional-sub-1',
        'additional-sub-2',
      ],
      parentKey: Utils.utilityHelpers.defaultKeys.MENU,
    }, {
      key: 'additional-sub-1',
      title: 'Additional Item 1 - Sub 1',
      parentKey: 'additional-1',
    }, {
      key: 'additional-sub-2',
      title: 'Additional Item 1 - Sub 2',
      parentKey: 'additional-1',
    }, {
      key: 'checkbox-item',
      title: 'Custom Checkbox Item',
      isSelectable: true,
      isSelected: checkboxItemEnabled,
      isReadOnly: false,
      parentKey: Utils.utilityHelpers.defaultKeys.MENU,
    }, {

render() {
    const { intl, location } = this.props;
    const { checkboxItemEnabled } = this.state;

    const customUtilityItems = [{
      key: 'additional-1',
      title: 'Drill-in Item',
      childKeys: [
        'additional-sub-1',
        'additional-sub-2',
      ],
      parentKey: Utils.utilityHelpers.defaultKeys.MENU,
    }, {
      key: 'additional-sub-1',
      title: 'Additional Item 1 - Sub 1',
      parentKey: 'additional-1',
    }, {
      key: 'additional-sub-2',
      title: 'Additional Item 1 - Sub 2',
      parentKey: 'additional-1',
    }, {
      key: 'checkbox-item',
      title: 'Custom Checkbox Item',
      isSelectable: true,
      isSelected: checkboxItemEnabled,
      isReadOnly: false,
      parentKey: Utils.utilityHelpers.defaultKeys.MENU,
    }, {

parentKey: Utils.utilityHelpers.defaultKeys.MENU,
    }, {
      key: 'additional-sub-1',
      title: 'Additional Item 1 - Sub 1',
      parentKey: 'additional-1',
    }, {
      key: 'additional-sub-2',
      title: 'Additional Item 1 - Sub 2',
      parentKey: 'additional-1',
    }, {
      key: 'checkbox-item',
      title: 'Custom Checkbox Item',
      isSelectable: true,
      isSelected: checkboxItemEnabled,
      isReadOnly: false,
      parentKey: Utils.utilityHelpers.defaultKeys.MENU,
    }, {
      key: 'readonly-item',
      title: 'Custom ReadOnly Item',
      isSelectable: true,
      isReadOnly: true,
      parentKey: Utils.utilityHelpers.defaultKeys.MENU,
    }, {
      key: 'additional-3',
      contentLocation: Utils.utilityHelpers.locations.FOOTER,
      title: 'Custom Footer',
      parentKey: Utils.utilityHelpers.defaultKeys.MENU,
    }];

    /**
     * The data provided for utilityConfig will be visible in the ApplicationLayout's header in the
     * standard rendering mode and within the menus in the compact rendering mode.