anchor.diff:          marquee.width = '100%';
   
           buildControls();
  +        accomponement.play();
       }
   
       void bindHandlers() {
  
positive.code:         final float mistakeRate = mistakeCount / totalChars;
          print('mistakeRate: ${mistakeRate * 100}%');
      }
  }
  
  TypeTrainer typeTrainer;
  
negative.code: 
  class TypeTrainer {
      MarqueeElement marquee;
      AudioElement accomponement;
      //    http://upload.wikimedia.org/wikipedia/commons/b/b1/11_-_Vivaldi_Winter_mvt_2_Largo_-_John_Harrison_violin.ogg
      //    http://upload.wikimedia.org/wikipedia/commons/2/21/12_-_Vivaldi_Winter_mvt_3_Allegro_-_John_Harrison_violin.ogg
  
      static final int spaceCharCode = 32;
      static final String cursor = '|';
  