anchor.diff:        appendOuput('---');
       }
     }
  -  
  +
     void pause() {
       if (subscription != null) {
         subscription.pause();
  
positive.code:       appendOuput('No subscription, cannot pause!');
      }
    }
    
    void resume() {
      if (subscription != null) {
        subscription.resume();
  
negative.code:       appendOuput('No subscription, cannot cancel!');
      }
    }
  
    void appendOuput(String text) {
      output.value += '$text\n';
      output.scrollTop = output.scrollHeight;
    }
  }
  