anchor.diff:              return _connectionPool.connect()
                 .then((connection) {
                   return connection.execute(
  -                      'UPDATE "world" SET "randomnumber" = @randomnumber WHERE "id" = @id;',
  +                      'UPDATE "World" SET "randomnumber" = @randomnumber WHERE "id" = @id;',
                         { 
                           'randomnumber': world.randomnumber,
                           'id': world.id 
  
positive.code:        var mongoConfig = yaml.loadYaml(config);
         _mongoDb = new Db("mongodb://${mongoConfig["host"]}/${mongoConfig["database"]}");
         return _mongoDb.open().then((_) {
           _worldCollection = _mongoDb.collection("world");
           _fortuneCollection = _mongoDb.collection("fortune");
         });
       })
     ]).then((_) {
  
negative.code: // MongoDB connection
  var _mongoDb;
  
  // World Collection
  var _worldCollection;
  
  // Fortunes Collection
  var _fortuneCollection;
  
  // World table size
  const _WORLD_TABLE_SIZE = 10000;
  // Fortune table size used only for generation of data
  const _FORTUNE_TABLE_SIZE = 100;
  
  final _RANDOM = new Random();
  
  class Fortune implements Comparable<Fortune> {
    int id;
  
    String message;
  
    Fortune(this.id, this.message);
  
    compareTo(Fortune other) => message.compareTo(other.message);
  }
  
  class World {
    int id;
    int randomnumber;
  
    World(this.id, this.randomnumber);
  
    toJson() => { "id": id, "randomnumber": randomnumber };
  }
  