Returns a list of rows sorted by start and end date.

        :param list[dict[str,T]] rows: The list of rows.

        :rtype: list[dict[str,T]]

def _rows_sort(self, rows):
        """
        Returns a list of rows sorted by start and end date.

        :param list[dict[str,T]] rows: The list of rows.

        :rtype: list[dict[str,T]]
        """
        return sorted(rows, key=lambda row: (row[self._key_start_date], row[self._key_end_date]))