anchor.diff:    int _currentposition = 0;
     String targettext;
     int _errors;
  -  Map<int,bool> typeCheck;
  +  Map<int,bool> typeCheck = new Map<int,bool>();
     
     Trainer(this.targettext);
   
  
positive.code:       default:
          var te = querySelector('#test');
          var typed = tinput.value.split('')[_currentposition];
          if (typed != charAtCurrentPosition()) {
            
          
  
negative.code:     var sofar = targettext.split('').getRange(0, _currentposition + 1);
      return 100 - (_errors.toDouble() / sofar.length.toDouble() * 100).round();
    }
    void checkAtPosition(int pos, String character) {
      typeCheck[pos] = (targettext.split('')[pos] == character);
    }
    
    void handleKeyEvent(Event e) {  
  