formatTime method
Implementation
String formatTime(int milliseconds) {
int seconds = (milliseconds / 1000).truncate() % 60;
int minutes = (milliseconds / 60000).truncate();
String minutesStr = (minutes % 60).toString().padLeft(2, '0');
String secondsStr = seconds.toString().padLeft(2, '0');
return '$minutesStr:$secondsStr';
}