code: func (engine *Engine) RunUnix(file string) (err error) {
  	debugPrint("Listening and serving HTTP on unix:/%s", file)
  	defer func() { debugPrintError(err) }()
  
  	os.Remove(file)
  	listener, err := net.Listen("unix", file)
  	if err != nil {
  		return
  	}
  	defer listener.Close()
  	os.Chmod(file, 0777)
  	err = http.Serve(listener, engine)
  	return
  }
docs: // RunUnix attaches the router to a http.Server and starts listening and serving HTTP requests
  // through the specified unix socket (ie. a file).
  // Note: this method will block the calling goroutine indefinitely unless an error happens.