nextUuid method
Gets the next value as a UUID-formatted String.
Implementation
String nextUuid() {
final hex = nextHex();
return hex.substring(0, 8) +
'-' +
hex.substring(8, 12) +
'-' +
hex.substring(12, 16) +
'-' +
hex.substring(16, 20) +
'-' +
hex.substring(20);
}