anchor.diff:    
     return _fortuneCollection.find().toList().then((fortunes) {
       fortunes = fortunes.map((fortune) {
  -      return new Fortune(fortune["id"], fortune["message"]);
  +      return new Fortune(fortune["_id"], fortune["message"]);
       }).toList();
       fortunes.add(new Fortune(0, 'Additional fortune added at request time.'));
       fortunes.sort();
  
positive.code:     .then((worlds) {
        var result = worlds.map((world) {
          return {
            "id": world["id"],
            "randomnumber": world["randomnumber"]
          };
        });
        connect.response.write(json.stringify(result.toList()));
  
negative.code:     .then((response) {
        var results = response.map((world) {
          return {
            "id": world["_id"],
            "randomNumber": world["randomNumber"]
          };
        });
        connect.response.write(json.stringify(results.toList()));
  