Attempts for connecting to tcp server

attempt.js

    var that = this
    var makeAttempt = function () {
        if (ports.length > 0) {
            net.createConnection({port: ports[0]}, function () {
                // test all ports
                ports.shift()
                makeAttempt()
            }).on("error", function (e) {
                attempt ++
                if (attempt < 100) {
                    setTimeout(makeAttempt, 200)
                } else {
                    exercise.emit('fail', 'Timeout occured')
                }
            })
        } else {
            query.call(that, mode)
            return
        }
    }
    makeAttempt()