anchor.diff:    const PlayedCard(this.card, this.dir, this.playerNum);
   
     Set<CardOrientation> exits() => CardUtil.exits(card.type, dir);
  -  
  +
     String toString() => "Played: {${card.toString()}, ${dir.toString()}, $playerNum}";
   
   }
  
positive.code:         return new BoardLoc(this.x + 1, this.y);
      }
    }
    
    int get hashCode {
      int result = 17;
      result = 37 * result + x;
  
negative.code: class Board {
    Map<BoardLoc, PlayedCard> boardMap;
    Set<BoardLoc> fringe;
  
    Board() {
      boardMap = new Map<BoardLoc, PlayedCard>();
      fringe = new Set<BoardLoc>.from([BoardLoc.origin]);
  
    }
  
    bool isClosed() => fringe.length == 0;
  
  }
  