code: def _unpublish(self):
          
          obj = self.content_object
          actioned = False
  
          # Only update if needed
          if obj.current_version is not None:
              obj.current_version = None
              obj.save(update_fields=['current_version'])
              actioned = True
  
          return actioned
docs: Process an unpublish action on the related object, returns a boolean if a change is made.
  
          Only objects with a current active version will be updated.