code: function getstat (dpath, _files, cb) {
      ;(function loop (index) {
        if (index == _files.length) return cb()
        var fpath = path.join(dpath, _files[index])
        fs.stat(fpath, function (err, stats) {
          if (err) return cb(err)
          if (stats.isDirectory()) {
            dirs.push(fpath)
          } else {
            files.push(fpath)
          }
          loop(++index)
        })
      }(0))
    }
docs: Get stat
  
  @param {String} directory path
  @param {Array} files
  @param {Function} callback
  @api private