code: func NewClient(cert tls.Certificate) (*http.Client, error) {
  	config := &tls.Config{
  		Certificates: []tls.Certificate{cert},
  	}
  	config.BuildNameToCertificate()
  	transport := &http.Transport{TLSClientConfig: config}
  
  	if err := http2.ConfigureTransport(transport); err != nil {
  		return nil, err
  	}
  
  	return &http.Client{Transport: transport}, nil
  }
docs: // NewClient sets up an HTTP/2 client for a certificate.