NavBar divider

Questions
1

I want to create a navbar menu and a submenu for one of the items.
In the submenu I want to programmatically add a divider instead of a MENU ITEM.
On the ide I can create the menu item and then the sub menu item and can set the isDivider to true.
How to do that for programming?
currently I use

	//admin
	menuItem = elements.navbar_zff_manager.createMenuItem('Admin', DEFAULT_NAVBAR_ACTIONS.ADMIN, 'LEFT');
	menuItem.displayType = 'MENU_ITEM';
	menuItem.iconName = 'fas fa-user-secret';
	menuItem.styleClass = 'no-border';

	var admin_submenuItems = [];
	//sub menu items for admin
	var subMenuItem = elements.navbar_zff_manager.createMenuItem('Admin-Tally-Viewer', DEFAULT_ADMIN_NAVBAR_ACTIONS.TALLY_VIEWER);
	subMenuItem.iconName = 'fas fa-adjust';
	admin_submenuItems.push(subMenuItem);

	//divider
	/** @type {CustomType <bootstrapextracomponents-navbar.menuItem.subMenuItem>} */
	subMenuItem = elements.navbar_zff_manager.createMenuItem('divider');
	subMenuItem.displayType = 'MENU_ITEM';
...tbd...
..
	admin_submenuItems.push(subMenuItem);
	//at the end of the admin sub menu items
	menuItem.subMenuItems = admin_submenuItems;

	menuItems.push(menuItem);

I am not sure the Custom Type is correct (I could not find a reference for it in wiki or other places).
I am not sure this is possible at all.