toHMS method
Prints a Duration with the format {hh:mm:ss}.
Implementation
String toHMS() {
String twoDigits(int n) => n.toString().padLeft(2, "0");
final String twoDigitMinutes = twoDigits(inMinutes.remainder(60));
final String twoDigitSeconds = twoDigits(inSeconds.remainder(60));
return "${twoDigits(inHours)}:$twoDigitMinutes:$twoDigitSeconds";
}