code: function create(upperdir, callback)
  {
    var workdir = upperdir.split('/')
    var user    = workdir.pop()
    var workdir = workdir.join('/')+'/.workdirs/'+user
  
    mkdirp(workdir, '0100', function(error)
    {
      if(error && error.code !== 'EEXIST') return callback(error)
  
      // Craft overlayed filesystem
      var type   = 'overlay'
      var extras =
      {
        lowerdir: '/',
        upperdir: upperdir,
        workdir : workdir
      }
  
      utils.mkdirMount(upperdir, type, MS_NOSUID, extras, function(error)
      {
        if(error) return callback(error)
  
        var arr =
        [
          {
            path: upperdir+'/dev',
            flags: MS_BIND,
            extras: {devFile: '/tmp/dev'}
          },
          {
            path: upperdir+'/proc',
            flags: MS_BIND,
            extras: {devFile: '/proc'}
          },
          {
            path: upperdir+'/tmp',
            type: 'tmpfs',
            flags: MS_NODEV | MS_NOSUID
          }
        ]
  
        each(arr, mkdirMountInfo, callback)
      })
    })
  }
docs: Public API  
  Execute the command file
  
  @param {String}   upperdir Path of the root of the container
  @param {Function} callback