generateV4 method
Implementation
String generateV4() {
// Generate xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx / 8-4-4-4-12.
final int special = 8 + _random.nextInt(4);
return '${_bitsDigits(16, 4)}${_bitsDigits(16, 4)}-'
'${_bitsDigits(16, 4)}-'
'4${_bitsDigits(12, 3)}-'
'${_printDigits(special, 1)}${_bitsDigits(12, 3)}-'
'${_bitsDigits(16, 4)}${_bitsDigits(16, 4)}${_bitsDigits(16, 4)}';
}