toClockString method
Returns a stopwatch-style string.
Implementation
String toClockString() {
final d = _abs;
final h = d.inHours;
final m = d.inMinutes % 60;
final s = d.inSeconds % 60;
final mm = '$m'.padLeft(2, '0');
final ss = '$s'.padLeft(2, '0');
final body = h > 0 ? '$h:$mm:$ss' : '$m:$ss';
return isNegative ? '-$body' : body;
}