generateGTIN function
Generate any type of gtin and adds check digit gtinLength
is the desired size with check digit
Implementation
String generateGTIN({int gtinLength = 14}) {
final random = Random();
// if length == 8 will generate 7 digit
final min = pow(10, gtinLength - 2) as int;
final max = 100000;
final list = (min + random.nextInt(max)).toString().split('');
final List<int> generated = list.map(int.parse).toList();
return generated.join('') + findCheckDigit(generated).toString();
}