code: func waitServer(url string) bool {
  	tries := 20
  	for tries > 0 {
  		resp, err := http.Get(url)
  		if err == nil {
  			resp.Body.Close()
  			return true
  		}
  		time.Sleep(100 * time.Millisecond)
  		tries--
  	}
  	return false
  }
docs: // waitServer waits some time for the http Server to start
  // serving url. The return value reports whether it starts.