code: def item_extra_kwargs(self, action):
          
          item = self.format(action)
          item.pop('title', None)
          item['uri'] = item.pop('url')
          item['activity:verb'] = item.pop('verb')
          return item
docs: Returns an extra keyword arguments dictionary that is used with
          the `add_item` call of the feed generator.
          Add the 'content' field of the 'Entry' item, to be used by the custom
          feed generator.