nextId static method
Returns UnitId.cycleId of current microsecondsSinceEpoch
and adds 4 random chars to end of String.
UnitId.aZn is used as input - so result is case sensitive and with numbers.
Implementation
static String nextId() {
final stamp = DateTime.now().toUtc().microsecondsSinceEpoch;
return cycleId(stamp, aZn) + randomId(length: 4, sequence: aZn);
}