if err != nil {
		if _, ok := err.(BackendDown); ok {
			return err
		}
		return tierPermErr{
			Op:  tierPut,
			Err: err,
		}
	}

	r, err := w.Get(ctx, probeObject, "", WarmBackendGetOpts{})
	xhttp.DrainBody(r)
	if err != nil {
		if _, ok := err.(BackendDown); ok {
			return err
		}
		switch {
		case isErrBucketNotFound(err):
			return errTierBucketNotFound
		case isErrSignatureDoesNotMatch(err):

}

func (b *streamingBitrotReader) Close() error {
	if b.rc == nil {
		return nil
	}
	if closer, ok := b.rc.(io.Closer); ok {
		// drain the body for connection reuse at network layer.
		xhttp.DrainBody(io.NopCloser(b.rc))
		return closer.Close()
	}
	return nil
}

func (b *streamingBitrotReader) ReadAt(buf []byte, offset int64) (int, error) {
	var err error
	if offset%b.shardSize != 0 {