Gtk.Notebook.prototype.set_current_page

function set_current_page(page_num:Number):void {
    // Gjs wrapper for gtk_notebook_set_current_page()
}

Switches to the page number page_num.

Note that due to historical reasons, GtkNotebook refuses to switch to a page unless the child widget is visible. Therefore, it is recommended to show child widgets before adding them to a notebook.