updateRow method
Implementation
void updateRow(int index, List<dynamic> values) {
if (values.length != columns.length) {
throw Exception('Values length must match columns');
}
for (int i = 0; i < columns.length; i++) {
data[index].cells[i].value = values[i];
}
data[index].isEditing = false;
_unsavedRows.remove(index);
notifyListeners();
}