Put(ctx context.Context, object string, r io.Reader, length int64) (remoteVersionID, error)
	PutWithMeta(ctx context.Context, object string, r io.Reader, length int64, meta map[string]string) (remoteVersionID, error)
	Get(ctx context.Context, object string, rv remoteVersionID, opts WarmBackendGetOpts) (io.ReadCloser, error)
	Remove(ctx context.Context, object string, rv remoteVersionID) error
	InUse(ctx context.Context) (bool, error)
}

	res, err := s3.client.PutObject(ctx, s3.Bucket, s3.getDest(object), r, length, minio.PutObjectOptions{
		SendContentMd5: true,
		StorageClass:   s3.StorageClass,
		UserMetadata:   meta,
	})
	return remoteVersionID(res.VersionID), s3.ToObjectError(err, object)
}

	if resp.VersionID != nil {
		vid = *resp.VersionID
	}
	return remoteVersionID(vid), nil
}

func (az *warmBackendAzure) Put(ctx context.Context, object string, r io.Reader, length int64) (remoteVersionID, error) {
	return az.PutWithMeta(ctx, object, r, length, map[string]string{})
}

func (az *warmBackendAzure) Get(ctx context.Context, object string, rv remoteVersionID, opts WarmBackendGetOpts) (r io.ReadCloser, err error) {

	}
	return partSize, nil
}

func (m *warmBackendMinIO) PutWithMeta(ctx context.Context, object string, r io.Reader, length int64, meta map[string]string) (remoteVersionID, error) {
	partSize, err := optimalPartSize(length)
	if err != nil {
		return remoteVersionID(""), err
	}
	res, err := m.client.PutObject(ctx, m.Bucket, m.getDest(object), r, length, minio.PutObjectOptions{
		StorageClass:         m.StorageClass,

// Currently it's a no-op.
func (gcs *warmBackendGCS) Put(ctx context.Context, key string, data io.Reader, length int64) (remoteVersionID, error) {
	return gcs.PutWithMeta(ctx, key, data, length, map[string]string{})
}

func (gcs *warmBackendGCS) Get(ctx context.Context, key string, rv remoteVersionID, opts WarmBackendGetOpts) (r io.ReadCloser, err error) {
	// GCS storage decompresses a gzipped object by default and returns the data.

	}

	pr, pw := xioutil.WaitPipe()
	go func() {
		err := er.getObjectWithFileInfo(ctx, bucket, object, 0, fi.Size, pw, fi, metaArr, onlineDisks)
		pw.CloseWithError(err)
	}()

	var rv remoteVersionID
	rv, err = tgtClient.PutWithMeta(ctx, destObj, pr, fi.Size, map[string]string{
		"name": object, // preserve the original name of the object on the remote tier object metadata.