anchor.diff:  <input #durationrest>
   <button (click)="setDurationRest(durationrest.value)">change</button>
   </p>
  -''', directives: const [NgIf])
  +<p>History:</p>
  +<ul>
  +    <li *ng-for="#time of times">
  +        {{time}}
  +    </li>
  +</ul>
  +''', directives: const [NgFor, NgIf])
   
   class Clock{
   
  
positive.code:     counter= prettyPrintTime(25*60);
      currentState = ClockState.pomodoro;
      currentDuration = startPomodoroAt;
    }
    
    void start() {
  
negative.code:     if( s < 0){ 
        updateState();
        setCounter();
        addToHistory();
        reset();
        return; 
      }
      counter = prettyPrintTime(s);
    }
  
    void addToHistory(){
      switch(currentState){
        case ClockState.pomodoro:
          times.add("rest");
          break;
        case ClockState.rest:
          times.add("pomodoro");
          break;
      }
    }
  
    void setDurationPomodoro(string duration){
  