Method _refuse_empty

lib/sqlalchemy/orm/collections.py:520–524

(self)

        )

    def _refuse_empty(self) -> NoReturn:
        raise sa_exc.InvalidRequestError(
            "This is a special 'empty' collection which cannot accommodate "
            "internal mutation operations"
        )

    def append_without_event(self, item: Any) -> None:
        """Add or restore an entity to the collection, firing no events."""