internal void VerifyRecord(int record)
{
Debug.Assert((record < _lastFreeRecord) && (-1 == _freeRecordList.IndexOf(record)), "accesing free record");
Debug.Assert((null == _rows[record]) ||
(record == _rows[record]._oldRecord) ||
(record == _rows[record]._newRecord) ||
(record == _rows[record]._tempRecord), "record of a different row");
}