anchor.diff:      var index = (symptomsCopy.length > 1) ? random.nextInt(symptomsCopy.length-1) : 0;
       print('Does this object has "${symptomsCopy[index]}" symptom (y/n)?');
       if (stdin.readLineSync() == 'y') {
  -      acceptedSymptoms.add(index);
  +      acceptedSymptoms.add(symptoms.indexOf(symptomsCopy[index]));
       }
       symptomsCopy.removeAt(index);
     }
  
positive.code:     while(chosenSymptoms.length < 2) {
        print('Enter one more symptom to describe this object:');
        symptoms.add(stdin.readLineSync());
        chosenSymptoms.add(symptoms.length);
      }
    } else {
      String objectName;
  
negative.code: Map objects = {};
  
  /**
   * Asks questions and returns a list of symptoms.
   */
  List<int> askQuestions() {
    var acceptedSymptoms=[];
  