checkDigit method
Computes the check digit from data
.
Implementation
@override
int checkDigit(String data) {
if (data.length != 12) {
throw ArgumentError('Must not be null and must contain 12 digits');
}
final sum1 = _compute(data, _multiplier1);
final r1 = sum1 % 11;
final v1 = r1 < 2 ? 0 : (11 - r1);
final sum2 = _compute(data, _multiplier2) + (v1 * 2);
final r2 = sum2 % 11;
final v2 = r2 < 2 ? 0 : (11 - r2);
return (v1 * 10) + v2;
}