Gtk.Notebook.prototype.get_menu_label

function get_menu_label(child:Gtk.Widget):Gtk.Widget {
    // Gjs wrapper for gtk_notebook_get_menu_label()
}

Retrieves the menu label widget of the page containing child.

child: a widget contained in a page of notebook
Returns: the menu label, or null if the notebook page does not have a menu label other than the default (the tab label).