snapshot method
Implementation
@override
Future<void> snapshot(FieldData fieldData, int ts, int user_ts) async {
if (!initialized) throw ArgumentError(AbstractDao.C_MUST_INIT);
TrDto lTrDto = TrDto.field(fieldData);
lTrDto.ts = ts;
lTrDto.operation = OperationType.SNAPSHOT;
lTrDto.user_id = 0;
lTrDto.user_ts = user_ts;
lTrDto.comment = "${tableTransactionDao.tableName} table Snapshot";
lTrDto.crc = null;
await tableTransactionTrDao.upsertTR(
lTrDto, lTrDto.getFieldDataNoTr, WhereData());
}