code: def update_properties_cache(sender, instance, action, reverse, model, pk_set, **kwargs):
      "Property cache actualization at POI save. It will not work yet after property removal."
      if action == 'post_add':
          instance.save_properties_cache(f update_properties_cache(sender, instance, action, reverse, model, pk_set, **kwargs):
      "Property cache actualization at POI save. It will not work yet after property removal."
      if action == 'post_add':
          instance.save_properties_cache()
docs: Property cache actualization at POI save. It will not work yet after property removal.