code: function generateOptionsResponder(res, methods) {
    return function onDone(fn, err) {
      if (err || methods.length === 0) {
        return fn(err)
      }
  
      trySendOptionsResponse(res, methods, fn)
    }
  }
docs: Generate a callback that will make an OPTIONS response.
  
  @param {OutgoingMessage} res
  @param {array} methods
  @private