code: func New(assetPath string, output io.Writer) *JSRE {
  	re := &JSRE{
  		assetPath:     assetPath,
  		output:        output,
  		closed:        make(chan struct{}),
  		evalQueue:     make(chan *evalReq),
  		stopEventLoop: make(chan bool),
  	}
  	go re.runEventLoop()
  	re.Set("loadScript", re.loadScript)
  	re.Set("inspect", re.prettyPrintJS)
  	return re
  }
docs: // runtime must be stopped with Stop() after use and cannot be used after stopping