How to use the terraform.root function in terraform

exports.pipeline = function(root){
  console.log("Deprecated, please use MOUNT instead, this will be removed in a future version.");
  var publicPath = path.resolve(root)
  var terra = terraform.root(publicPath)

  return function(req, rsp, next){
    var normalizedPath  = helpers.normalizeUrl(req.url)
    var priorityList    = terraform.helpers.buildPriorityList(normalizedPath)
    var sourceFile      = terraform.helpers.findFirstFile(publicPath, priorityList)

    if(!sourceFile) return next()

    terra.render(sourceFile, function(error, body){
      if(error) return next(error)
      if(!body) return next() // 404

      var outputType = terraform.helpers.outputType(sourceFile)
      var mimeType   = helpers.mimeType(outputType)
      var charset    = mime.charsets.lookup(mimeType)
      rsp.statusCode = 200

var charset    = mime.charsets.lookup(mimeType)
          var body       = helpers.cssError(locals)
          rsp.statusCode = 200
          rsp.setHeader('Content-Type', mimeType + (charset ? '; charset=' + charset : ''))
          rsp.setHeader('Content-Length', Buffer.byteLength(body, charset));
          rsp.end(body)
        }else{

          // Make the paths relative but keep the root dir.
          // TODO: move to helper.
          //
          // var loc = req.projectPath.split(path.sep); loc.pop()
          // var loc = loc.join(path.sep) + path.sep
          // if(error.filename) error.filename = error.filename.replace(loc, "")

          terraform.root(__dirname + "/templates").render("error.jade", locals, function(err, body){
            var mimeType   = helpers.mimeType('html')
            var charset    = mime.charsets.lookup(mimeType)
            rsp.statusCode = 500
            rsp.setHeader('Content-Type', mimeType + (charset ? '; charset=' + charset : ''))
            rsp.setHeader('Content-Length', Buffer.byteLength(body, charset));
            rsp.end(body)
          })
        }
      }else{
        // 404
        if(!body) return next()

        var outputType = terraform.helpers.outputType(sourceFile)
        var mimeType   = helpers.mimeType(outputType)
        var charset    = mime.charsets.lookup(mimeType)
        rsp.statusCode = 200

return function(req, rsp, next){
    var host      = req.headers.host;
    var hostname  = host.split(':')[0];
    var arr       = hostname.split(".");
    var port      = host.split(':')[1] ? ':' + host.split(':')[1] : '';
    var poly      = terraform.root(__dirname + "/templates");

    if(arr.length == 2){
      fs.readdir(dirPath, function(err, files){
        var projects = [];

        files.forEach(function(file){
          var local = file.split('.');

          var appPart = local.join("_");

          if (local.length > 2) {
            var domain = local.slice(Math.max(local.length - 2, 1)).join(".");
            if (reservedDomains.indexOf(domain) != -1) {
              appPart =  local[0];
            }
          }

var poly = exports.poly = function(req, rsp, next){
  if(req.hasOwnProperty("poly")) return next()

  try{
    req.poly = terraform.root(req.setup.publicPath, req.setup.config.globals)
  }catch(error){
    error.stack = helpers.stacktrace(error.stack, { lineno: error.lineno })
    var locals = {
      project: req.headers.host,
      error: error,
      pkg: pkg
    }
    return terraform.root(__dirname + "/templates").render("error.jade", locals, function(err, body){
      rsp.statusCode = 500
      rsp.end(body)
    })
  }
  next()
}

outputPath = "www"
  }

  if(!outputPath){
    outputPath = "www"
  }


  /**
   * Setup all the paths and collect all the data
   */

  try{
    outputPath = path.resolve(projectPath, outputPath)
    var setup  = helpers.setup(projectPath, "production")
    var terra   = terraform.root(setup.publicPath, setup.config.globals)
  }catch(err){
    return callback(err)
  }


  /**
   * Protect the user (as much as possible) from compiling up the tree
   * resulting in the project deleting its own source code.
   */

  if(!helpers.willAllow(projectPath, outputPath)){
    return callback({
      type: "Invalid Output Path",
      message: "Output path cannot be greater then one level up from project path and must be in directory starting with `_` (underscore).",
      projectPath: projectPath,
      outputPath: outputPath