code: def tracking_save(sender, instance, raw, using, update_fields, **kwargs):
      
      if _has_changed(instance):
          if instance._original_fields['pk'] is None:
              # Create
              _create_create_tracking_event(instance)
          else:
              # Update
              _create_update_tracking_event(instance)
      if _has_changed_related(instance):
          # Because an object need to be saved before being related,
          # it can only be an update
          _create_update_tracking_related_event(instance)
      if _has_changed(instance) or _has_changed_related(instance):
          _set_original_fields(instance)
docs: Post save, detect creation or changes and log them.
      We need post_save to have the object for a create.