code: function recess(init, path, err) {
      if (path = paths.shift()) {
        return instances.push(new RECESS(path, options, recess))
      }
  
      // map/filter for errors
      err = instances
        .map(function (i) {
          return i.errors.length && i.errors
        })
        .filter(function (i) {
          return i
        })
  
      // if no error, set explicitly to null
      err = err.length ? err[0] : null
  
      //callback
      callback && callback(err, instances)
    }
docs: for each path, create a new RECESS instance