toTimeString method
Implementation
String toTimeString() {
int seconds = this % 60;
int totalMinutes = (this / 60).floor();
int minutes = totalMinutes % 60;
int hours = (totalMinutes / 60).floor();
String hoursString = hours.toString().padLeft(2, '0');
String minutesString = minutes.toString().padLeft(2, '0');
String secondsString = seconds.toString().padLeft(2, '0');
//HH:mm:ss
return '$hoursString:$minutesString:$secondsString';
}