code: def _build_list_item(self, item_value, id_=None):
          
          return {
              '$type': self._type_map[self.input_type]['list_item_type'],
              'id': id_ or SID.generate(),
              'value': item_value
          }
docs: Return a dict with ID and $type for API representation of value
  
          Uses id_ param if provided, defaults to new random ID