code: func SetTransportDefaults(t *http.Transport) *http.Transport {
  	t = SetOldTransportDefaults(t)
  	// Allow clients to disable http2 if needed.
  	if s := os.Getenv("DISABLE_HTTP2"); len(s) > 0 {
  		klog.Infof("HTTP2 has been explicitly disabled")
  	} else {
  		if err := http2.ConfigureTransport(t); err != nil {
  			klog.Warningf("Transport failed http2 configuration: %v", err)
  		}
  	}
  	return t
  }
docs: // SetTransportDefaults applies the defaults from http.DefaultTransport
  // for the Proxy, Dial, and TLSHandshakeTimeout fields if unset