anchor.diff:    }
   
     void updateTimeRemaining(Timer _) {
  -    var s  = startAt - watch.elapsedMilliseconds~/1000;
  +    var s  = startPomodoroAt - watch.elapsedMilliseconds~/1000;
       
       if( s < 0){ 
         stop();
  
positive.code:   void setDurationPomodoro(string duration){
      var value = int.parse(duration, onError: (source) => null);
      if (value != null){
        startAt = value*60;
        durationPomodoro = prettyPrintTime(startAt);
        counter = durationPomodoro;
      }
    }
  
negative.code: 
  class Clock{
  
    int startPomodoroAt, startBreakAt;
    String durationBreak, durationPomodoro;
    String counter;
    Stopwatch watch = new Stopwatch();
    Timer timer;
  
    Clock(){
      startPomodoroAt = (25*60);
      startBreakAt = (5*60);
      durationBreak = prettyPrintTime(startBreakAt);
      durationPomodoro = prettyPrintTime(startPomodoroAt);
      counter= prettyPrintTime(25*60);
    }
    
  