def check_single_result_rows_count(rows: Sequence[Optional["T"]]) -> None:
        """
        Verifies if the result has one and only one row.

        :param rows: one element list of Models
        :type rows: List[Model]
        """
        if not rows or rows[0] is None:
            raise NoMatch()
        if len(rows) > 1:
            raise MultipleMatches()

        Verifies if the result has one and only one row.

        :param rows: one element list of Models
        :type rows: List[Model]
        
ormar/queryset/queryset.py