code: def _store(self, message_key: str, result: Result, ttl: int) -> None:  # pragma: no cover
          
          raise NotImplementedError("%(classname)r does not implement _store()" % {
              "classname": type(self).__name__,
          })
docs: Store a result in the backend.  Subclasses may implement
          this method if they want to use the default implementation of
          set_result.