Gtk.Notebook.prototype.get_tab_label_text

function get_tab_label_text(child:Gtk.Widget):String {
    // Gjs wrapper for gtk_notebook_get_tab_label_text()
}

Retrieves the text of the tab label for the page containing child.

child: a widget contained in a page of notebook
Returns: the text of the tab label, or null if the tab label widget is not a Gtk.Label. The string is owned by the widget and must not be freed.