code: def _log_action(self):
          
          if self.publish_version == self.UNPUBLISH_CHOICE:
              message = 'Unpublished page (scheduled)'
          else:
              message = 'Published version {} (scheduled)'.format(self.publish_version)
  
          LogEntry.objects.log_action(
              user_id=self.user.pk,
              content_type_id=self.content_type.pk,
              object_id=self.object_id,
              object_repr=force_text(self.content_object),
              action_flag=CHANGE,
              change_message=message
          )
docs: Adds a log entry for this action to the object history in the Django admin.