anchor.diff:  
   class Room extends Card {
     const Room._(name):super(name);
  -  const static List<Room> all = [HALL, STUDY, LIBRARY, CONSERVATORY, 
  +  static const List<Room> all = [HALL, STUDY, LIBRARY, CONSERVATORY, 
     BALL_ROOM, BILLIARD_ROOM, LOUNGE, DINING_ROOM, KITCHEN];
     
     static final Room HALL =
  
positive.code: 
  class Character extends Card {
    const Character._(name):super(name);
    const static List<Character> all = [SCARLET, MUSTARD, WHITE, GREEN, PEACOCK, PLUM];
    
    static final Character SCARLET =
        const Character._("SCARLET");
  
negative.code: 
  class Weapon extends Card {
    const Weapon._(name):super(name);
    static const List<Weapon> all = [KNIFE, CANDLESTICK, PIPE, PISTOL, ROPE, POISON];
    
    static final Weapon KNIFE =
        const Weapon._("KNIFE");
  