code: def str_id(self):
          "str: This key's string id."
          id_or_name = self.id_or_name
          if id_or_name is not None and isinstance(id_or_name, str):
              return id_or_name
          return Nonf str_id(self):
          "str: This key's string id."
          id_or_name = self.id_or_name
          if id_or_name is not None and isinstance(id_or_name, str):
              return id_or_name
          return None
docs: str: This key's string id.