return &k.PublicKey
		case *ecdsa.PrivateKey:
			return &k.PublicKey
		default:
			return nil
		}
	}

	pemBlockForKey := func(priv interface{}) *pem.Block {
		switch k := priv.(type) {
		case *rsa.PrivateKey:
			return &pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(k)}
		case *ecdsa.PrivateKey:
			b, err := x509.MarshalECPrivateKey(k)
			if err != nil {

		if len(result.Uploads) != 0 {
			return z.serverPools[idx].NewMultipartUpload(ctx, bucket, object, opts)
		}
	}

	// any parallel writes on the object will block for this poolIdx
	// to return since this holds a read lock on the namespace.
	idx, err := z.getPoolIdx(ctx, bucket, object, -1)
	if err != nil {
		return nil, err
	}

	onlineDisks, metaArr = shuffleDisksAndPartsMetadataByIndex(onlineDisks, metaArr, fi)

	// For negative length read everything.
	if length < 0 {
		length = fi.Size - startOffset
	}

	// Reply back invalid range if the input offset and length fall out of range.
	if startOffset > fi.Size || startOffset+length > fi.Size {
		return InvalidRange{startOffset, length, fi.Size}
	}

	// Get start part index and offset.

	}
	var uploadedParts []CompletePart
	res, err := api.NewMultipartUpload(context.Background(), tgtBucket, tgtObject, opts)
	if err != nil {
		return err
	}

	defer func() {
		if err != nil {
			// block and abort remote upload upon failure.
			attempts := 1
			for attempts <= 3 {
				aerr := api.AbortMultipartUpload(ctx, tgtBucket, tgtObject, res.UploadID, ObjectOptions{})
				if aerr == nil {
					return
				}