code: def clean_cache(self, request):
          
          treenav.delete_cache()
          self.message_user(request, _('Cache menuitem cache cleaned 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: Remove all MenuItems from Cache.