anchor.diff:    cards.add(Character.PEACOCK);
     cards.add(Character.PLUM);
       
  -  cards.add(Room.BALLROOM);
  -  cards.add(Room.BILLIARDROOM);
  +  cards.add(Room.BALL_ROOM);
  +  cards.add(Room.BILLIARD_ROOM);
     cards.add(Room.CONSERVATORY);
  -  cards.add(Room.DININGROOM);
  +  cards.add(Room.DINING_ROOM);
     cards.add(Room.HALL);
     cards.add(Room.KITCHEN);
     cards.add(Room.LIBRARY);
  
positive.code: 
  class Room extends Card {
    const Room._(name):super(name);
    
    static final Room HALL =
        const Room._("HALL");
  
negative.code:   cards.removeAt(cards.indexOf(winners.room));
    cards.removeAt(cards.indexOf(winners.weapon));
    cards.removeAt(cards.indexOf(winners.character));
  
    return shuffleDeck(shuffleDeck(shuffleDeck(cards)));
  }
  
  List<Card> shuffleDeck(List<Card> cards){
    //TODO shuffle deck
    
    return cards;
  }
  