code: function init (dirname, done) {
      dirname = path.join(basedir, dirname)
      fs.access(dirname, function (err) {
        if (err) return done()
        readdir(dirname, function (err, _list) {
          if (err) return done(err)
          list = list.concat(_list)
          done()
        })
      })
    }
docs: Run only once at the start of the pass.