# toString method

String toString ()

Returns a string representation of this `Duration`.

Returns a string with hours, minutes, seconds, and microseconds, in the following format: `HH:MM:SS.mmmmmm`. For example,

    var d = new Duration(days:1, hours:1, minutes:33, microseconds: 500);
    d.toString();  // "25:33:00.000500"

## Implementation

    String toString() {
      String sixDigits(int n) {
        if (n >= 100000) return "$n";
        if (n >= 10000) return "0$n";
        if (n >= 1000) return "00$n";
        if (n >= 100) return "000$n";
        if (n >= 10) return "0000$n";
        return "00000$n";
      }

      String twoDigits(int n) {
        if (n >= 10) return "$n";
        return "0$n";
      }

      if (inMicroseconds < 0) {
        return "-${-this}";
      }
      String twoDigitMinutes = twoDigits(inMinutes.remainder(minutesPerHour));
      String twoDigitSeconds = twoDigits(inSeconds.remainder(secondsPerMinute));
      String sixDigitUs =
          sixDigits(inMicroseconds.remainder(microsecondsPerSecond));
      return "$inHours:$twoDigitMinutes:$twoDigitSeconds.$sixDigitUs";
    }