gio:menu-item-new-submenu (label submenu)

label -- a string with the section label, or nil
submenu -- a g:menu-model object with the menu items of the submenu

The new g:menu-item object.

Creates a new g:menu-item object representing a submenu. This is a convenience API around the g:menu-item-new and g:menu-item-set-submenu functions.