return t.DialTLS != nil || t.DialTLSContext != nil
}

var http2client = godebug.New("http2client")

// onceSetNextProtoDefaults initializes TLSNextProto.
// It must be called via t.nextProtoOnce.Do.
func (t *Transport) onceSetNextProtoDefaults() {
	t.tlsNextProtoWasNil = (t.TLSNextProto == nil)
	if http2client.Value() == "0" {
		http2client.IncNonDefault()
		return
	}