anchor.diff:  <button (click)="start()">Start</button>
   <button (click)="stop()">Stop</button>
   <button (click)="reset()">Reset</button>
  +<p *ng-if="isPomotime()">Currently in pomodoro</p>
  +<p *ng-if="!isPomotime()">Currently in rest</p>
   <p>Pomodoro duration: <i>{{ durationPomodoro }}</i>
   <input #durationpomodoro>
   <button (click)="setDurationPomodoro(durationpomodoro.value)">change</button>
  
positive.code: import 'dart:async';
  
  import 'package:angular2/angular2.dart';
  
  @Component(selector: 'clock')
  
  
negative.code:     String second = (s <= 9) ? '0$s' : '$s';
      return '$minute:$second';
    }
  
    bool isPomotime(){
      return currentState == ClockState.pomodoro;
    }
  }