printDuration function
Implementation
String printDuration(Duration duration) {
//String negativeSign = duration.isNegative ? '-' : '';
String twoDigits(int n) => n.toString().padLeft(2, "0");
String twoDigitMinutes = twoDigits(duration.inMinutes.remainder(60).abs());
String twoDigitSeconds = twoDigits(duration.inSeconds.remainder(60).abs());
//return "$negativeSign${twoDigits(duration.inHours)}:$twoDigitMinutes:$twoDigitSeconds";
return "$twoDigitMinutes:$twoDigitSeconds";
}