replacing method

TimeOfDay replacing ({int hour, int minute })

Returns a new TimeOfDay with the hour and/or minute replaced.

Implementation 

TimeOfDay replacing({ int hour, int minute }) {
  assert(hour == null || (hour >= 0 && hour < hoursPerDay));
  assert(minute == null || (minute >= 0 && minute < minutesPerHour));
  return TimeOfDay(hour: hour ?? this.hour, minute: minute ?? this.minute);
}