def METHOD_NAME(self, widget, *args):
    if widget.get_active():
        create_gtk_user_override(self.settings, "gtk3", self)
    else:
        remove_gtk_user_override(self.settings, "gtk3", self)
    logging.debug(
        f"user-flatpak-theming-gtk3: {self.settings.get_boolean('user-flatpak-theming-gtk3')}"
    )