code: def refresh_hrefs(self, request):
          
          for item in treenav.MenuItem.objects.all():
              item.save()  # refreshes the HREF
          self.message_user(request, _('Menu item HREFs refreshed successfully.'))
          info = self.model._meta.app_label, self.model._meta.model_name
          changelist_url = reverse('admin:%s_%s_changelist' % info, current_app=self.admin_site.name)
          return redirect(changelist_url)
docs: Refresh all the cached menu item HREFs in the database.