return err
	}
	span.AddEvent("Txn call succeeded")

	if !txnResp.Succeeded {
		return storage.NewKeyExistsError(preparedKey, 0)
	}

	if out != nil {
		putResp := txnResp.Responses[0].GetResponsePut()
		err = decode(s.codec, s.versioner, data, out, putResp.Header.Revision)
		if err != nil {
			span.AddEvent("decode failed", attribute.Int("len", len(data)), attribute.String("err", err.Error()))