code: def format_item(self, action, item_type='actor'):
          
          obj = getattr(action, item_type)
          return {
              'id': self.get_uri(action, obj),
              'url': self.get_url(action, obj),
              'objectType': ContentType.objects.get_for_model(obj).name,
              'displayName': text_type(obj)
          }
docs: Returns a formatted dictionary for an individual item based on the action and item_type.