return "", gcsToObjectError(err, gcs.Bucket, key)
	}

	if _, err := xioutil.Copy(w, data); err != nil {
		return "", gcsToObjectError(err, gcs.Bucket, key)
	}

	return "", w.Close()
}

// FIXME: add support for remote version ID in GCS remote tier and remove this.
// Currently it's a no-op.
func (gcs *warmBackendGCS) Put(ctx context.Context, key string, data io.Reader, length int64) (remoteVersionID, error) {