if lookupHost == nil {
		lookupHost = net.DefaultResolver.LookupHost
	}

	if baseDialCtx == nil {
		// This is same as which `http.DefaultTransport` uses.
		baseDialCtx = (&net.Dialer{
			Timeout:   30 * time.Second,
			KeepAlive: 30 * time.Second,
		}).DialContext
	}

	return func(ctx context.Context, network, addr string) (conn net.Conn, err error) {
		host, port, err := net.SplitHostPort(addr)