code: func fallbackDial(proto, addr string, tlsConfig *tls.Config) (net.Conn, error) {
  	if tlsConfig != nil && proto != "unix" && proto != "npipe" {
  		return tls.Dial(proto, addr, tlsConfig)
  	}
  	if proto == "npipe" {
  		return sockets.DialPipe(addr, 32*time.Second)
  	}
  	return net.Dial(proto, addr)
  }
docs: // fallbackDial is used when WithDialer() was not called.
  // See cli.Dialer().