def _assert_results(
        self,
        ids_with_current_snapshot_records: Iterable,
        ids_with_closed_out_snapshot_records: Iterable,
    ):
        """
        All test cases are checked by considering whether a source record's id has a value in `dbt_valid_to`
        in `snapshot`. Each id can fall into one of the following cases:

        - The id has only one record in `snapshot`; it has a value in `dbt_valid_to`
            - the record was hard deleted in the source
        - The id has only one record in `snapshot`; it does not have a value in `dbt_valid_to`
            - the record was not updated in the source
            - the record was updated in the source, but not in a way that is tracked (e.g. via `strategy='check'`)
        - The id has two records in `snapshot`; one has a value in `dbt_valid_to`, the other does not
            - the record was altered in the source in a way that is tracked
            - the record was hard deleted and revived

        Note: Because of the third scenario, ids may show up in both arguments of this method.

        Args:
            ids_with_current_snapshot_records: a list/set/etc. of ids which aren't end-dated
            ids_with_closed_out_snapshot_records: a list/set/etc. of ids which are end-dated
        """
        records = set(self.get_snapshot_records("id, dbt_valid_to is null as is_current"))
        expected_records = set().union(
            {(i, True) for i in ids_with_current_snapshot_records},
            {(i, False) for i in ids_with_closed_out_snapshot_records},
        )
        for record in records:
            assert record in expected_records

        All test cases are checked by considering whether a source record's id has a value in `dbt_valid_to`
        in `snapshot`. Each id can fall into one of the following cases:

        - The id has only one record in `snapshot`; it has a value in `dbt_valid_to`
            - the record was hard deleted in the source
        - The id has only one record in `snapshot`; it does not have a value in `dbt_valid_to`
            - the record was not updated in the source
            - the record was updated in the source, but not in a way that is tracked (e.g. via `strategy='check'`)
        - The id has two records in `snapshot`; one has a value in `dbt_valid_to`, the other does not
            - the record was altered in the source in a way that is tracked
            - the record was hard deleted and revived

        Note: Because of the third scenario, ids may show up in both arguments of this method.

        Args:
            ids_with_current_snapshot_records: a list/set/etc. of ids which aren't end-dated
            ids_with_closed_out_snapshot_records: a list/set/etc. of ids which are end-dated
        
tests/functional/adapter/simple_snapshot/test_snapshot.py