docs: def with_json_path(self, path, field=None):
          """Annotate Storage objects with a specific JSON path.
  
          :param path: Path to get inside the stored object, which can be
              either a list of path components or a comma-separated
              string
          :param field: Optional output field name
          """
          if field is None:
              field = '_'.join(['json'] + json_path_components(path))
  
          kwargs = {field: JsonGetPath('json', path)}
          return self.defer('json').annotate(**kwargs)