Gtk.Notebook.prototype.prepend_page_menu

function prepend_page_menu(child:Gtk.Widget, tab_label:Gtk.Widget, menu_label:Gtk.Widget):Number {
    // Gjs wrapper for gtk_notebook_prepend_page_menu()
}

Prepends a page to notebook, specifying the widget to use as the label in the popup menu.

child: the Gtk.Widget to use as the contents of the page
tab_label: the Gtk.Widget to be used as the label for the page, or null to use the default label, 'page N'
menu_label: the widget to use as a label for the page-switch menu, if that is enabled. If null, and tab_label is a Gtk.Label or null, then the menu label will be a newly created label with the same text as tab_label; if tab_label is not a Gtk.Label, menu_label must be specified if the page-switch menu is to be used.
Returns: the index (starting from 0) of the prepended page in the notebook, or -1 if function fails