formatHHMMSS static method
Format duration as HH:MM:SS
Implementation
static String formatHHMMSS(Duration duration) {
final hours = duration.inHours;
final minutes = duration.inMinutes % 60;
final seconds = duration.inSeconds % 60;
return '${hours.toString().padLeft(2, '0')}:${minutes.toString().padLeft(2, '0')}:${seconds.toString().padLeft(2, '0')}';
}