Method _checkin_failed

lib/sqlalchemy/pool/base.py:741–747

(
        self, err: BaseException, _fairy_was_created: bool = True
    )

        return fairy

    def _checkin_failed(
        self, err: BaseException, _fairy_was_created: bool = True
    ) -> None:
        self.invalidate(e=err)
        self.checkin(
            _fairy_was_created=_fairy_was_created,
        )

    def checkin(self, _fairy_was_created: bool = True) -> None:
        if self.fairy_ref is None and _fairy_was_created: