async

    /**
     * @param {{ gameId: string, userId: string }} data
     * @param {Function} done
     * @returns {*}
     */
    connectionMessage: function(data, done) {
        var that = this;

        async.waterfall([
            function(next) {
                ApiUser.findOne({ _id: data.userId }, next);
            },
            function(user, next) {
                if (!user) {
                    return next(new ErrorMessage(ErrorMessage.USER_NOT_FOUND));
                }

                that.id = user._id.toString();
                that.login = user.login;
                ApiGame.findOne({ _id: data.gameId }, next);
            },
            function(apiGame, next) {
                try {
                    if (!apiGame) {
                        throw new ErrorMessage(ErrorMessage.GAME_NOT_FOUND);
                    } else if (apiGame.status === ApiGame.STATUS_STARTED) {
                        throw new ErrorMessage(ErrorMessage.GAME_IS_STARTED);
                    } else if (apiGame.status === ApiGame.STATUS_FINISHED) {
                        throw new ErrorMessage(ErrorMessage.GAME_IS_FINISHED);
                    }

                    var game = Game.findById(data.gameId) || new Game(data.gameId, apiGame.type);
                    if (game.isStarted) {
                        throw new ErrorMessage(ErrorMessage.GAME_IS_STARTED);
                    } else if (game.isFull()) {
                        throw new ErrorMessage(ErrorMessage.GAME_IS_FULL);
                    }

                    that.connectToGame(game);

                    // increment online
                    // change status to pending on first connection
                    var update = { $inc: { online: 1 } };
                    if (apiGame.status === ApiGame.STATUS_CREATED) {
                        update.$set = { status: ApiGame.STATUS_PENDING };
                    }
                    ApiGame.update({ _id: game.id }, update, next);
                } catch (err) {
                    next(err);
                }
            },
            function(number, res, next) {
                if (!config.features.autoStart || !that.game.isFull()) {
                    return next();
                }

                async.parallel([
                    that.game.start.bind(that.game),
                    ApiGame.update.bind(ApiGame, { _id: that.game.id }, { status: ApiGame.STATUS_STARTED })
                ], next);
            }
        ], function(err) {
            try {
                if (err instanceof ErrorMessage) {
                    that.send(err);
                } else if (err) {
                    throw err;
                }
                done();
            } catch (e) {
                done(e);
            }
        });
    },