appendRow method
Appends row
iterables just post the last filled index in the sheet
If sheet
does not exist then it will be automatically created.
Implementation
void appendRow(String sheet, List<dynamic> row) {
if (row.length == 0) {
return;
}
_availSheet(sheet);
int targetRow = _sheetMap[sheet]!.maxRows;
insertRowIterables(sheet, row, targetRow);
}