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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _rows_int2date(self, rows):
 """ Replaces start and end dates in the row set with their integer representation :param list[dict[str,T]] rows: The list of rows. """

        for row in rows:
            if self._date_type == 'str':
                row[self._key_start_date] = datetime.date.fromordinal(row[self._key_start_date]).isoformat()
                row[self._key_end_date] = datetime.date.fromordinal(row[self._key_end_date]).isoformat()
            elif self._date_type == 'date':
                row[self._key_start_date] = datetime.date.fromordinal(row[self._key_start_date])
                row[self._key_end_date] = datetime.date.fromordinal(row[self._key_end_date])
            elif self._date_type == 'int':
                # Nothing to do.
                pass
            else:
                raise ValueError('Unexpected date type {0!s}'.format(self._date_type))