How to use the mqtt-connection.generateStream function in mqtt-connection

var test            = require('tape').test
  , mqtt            = require('mqtt-connection')
  , parseStream     = mqtt.parseStream
  , generateStream  = mqtt.generateStream
  , through         = require('through2')
  , reduplexer      = require('reduplexer')
  , aedes           = require('../')
  , clients         = 0

function setup(broker) {
  var inStream  = generateStream()
    , outStream = parseStream()
    , conn      = reduplexer(outStream, inStream)

  broker = broker || aedes()

  broker.handle(conn)

  conn.destroy = function() {
    inStream.destroy()

'use strict'

var mqtt = require('mqtt-connection')
var through = require('through2')
var aedes = require('../')
var duplexify = require('duplexify')
var parseStream = mqtt.parseStream
var generateStream = mqtt.generateStream
var clients = 0

function setup (broker, autoClose) {
  var inStream = generateStream()
  var outStream = parseStream()
  var conn = duplexify(outStream, inStream)

  broker = broker || aedes()

  broker.handle(conn)

  if (autoClose === undefined || autoClose) {
    setTimeout(function () {
      broker.close()
    }, autoClose || 200)
  }