Method _validate_persistent

lib/sqlalchemy/orm/session.py:4293–4298

(self, state: InstanceState[Any])

        return merged

    def _validate_persistent(self, state: InstanceState[Any]) -> None:
        if not self.identity_map.contains_state(state):
            raise sa_exc.InvalidRequestError(
                "Instance '%s' is not persistent within this Session"
                % state_str(state)
            )

    def _save_impl(self, state: InstanceState[Any]) -> None:
        if state.key is not None: