sum := r.md5.Sum(nil)
	return ETag(sum)
}

// VerifyError is an error signaling that a
// computed ETag does not match an expected
// ETag.
type VerifyError struct {
	Expected ETag
	Computed ETag
}

func (v VerifyError) Error() string {
	return fmt.Sprintf("etag: expected ETag %q does not match computed ETag %q", v.Expected, v.Computed)
}

// UUIDHash - use uuid to make md5sum

	// Complete multipart.
	parts := []CompletePart{
		{ETag: etag1, PartNumber: 1},
		{ETag: etag2, PartNumber: 2},
	}
	_, err = obj.CompleteMultipartUpload(context.Background(), bucket, object, uploadID, parts, ObjectOptions{})
	if err != nil {
		// Failed to complete multipart upload, abort.
		t.Fatalf("%s : %s", instanceType, err.Error())
	}

	for _, disk := range disks {
		tmpMetaDir := path.Join(disk, minioMetaTmpBucket)

		if _, err := io.Copy(io.Discard, reader); err != nil {
			t.Fatalf("Test %d: read failed: %v", i, err)
		}
		if ETag := reader.ETag(); !Equal(ETag, test.ETag) {
			t.Fatalf("Test %d: ETag mismatch: got %q - want %q", i, ETag, test.ETag)
		}
	}
}

var multipartTests = []struct { // Test cases have been generated using AWS S3
	ETags     []ETag
	Multipart ETag
}{
	{

		{[]CompletePart{{ETag: "wrong-md5-hash-string"}}, "0deb8cb07527b4b2669c861cb9653607-1", ""},

		// Single CompletePart with valid MD5 hash string.
		{[]CompletePart{{ETag: "cf1f738a5924e645913c984e0fe3d708"}}, "10dc1617fbcf0bd0858048cb96e6bd77-1", ""},

		// Multiple CompletePart with valid MD5 hash string.

	return partKey
}

// SealETag seals the etag using the object key.
// It does not encrypt empty ETags because such ETags indicate
// that the S3 client hasn't sent an ETag = MD5(object) and
// the backend can pick an ETag value.
func (key ObjectKey) SealETag(etag []byte) []byte {
	if len(etag) == 0 { // don't encrypt empty ETag - only if client sent ETag = MD5(object)
		return etag
	}
	var buffer bytes.Buffer

		// Test Case 3: if-match with wrong ETag
		// Even if the ETag doesn't match, we should still get read quorum error
		// because we can't read the object to check the condition.
		opts := ObjectOptions{
			UserDefined: map[string]string{
				xhttp.IfMatch: "wrong-etag",
			},
			CheckPrecondFn: func(oi ObjectInfo) bool {
				// Precondition fails if ETag doesn't match

// generates CopyObjectResponse from etag and lastModified time.
func generateCopyObjectResponse(etag string, lastModified time.Time) CopyObjectResponse {
	return CopyObjectResponse{
		ETag:         "\"" + etag + "\"",
		LastModified: amztime.ISO8601Format(lastModified.UTC()),
	}
}

// generates CopyObjectPartResponse from etag and lastModified time.

	PART_ETAG=$(echo "${UPLOAD_PART_OUT}" | jq '.ETag')
	if [ "${idx}" == 10 ]; then
		PARTS="${PARTS}{\"ETag\": ${PART_ETAG}, \"ChecksumSHA256\": \"${PART_CHKSUM}\", \"PartNumber\": ${idx}}"
	else
		PARTS="${PARTS}{\"ETag\": ${PART_ETAG}, \"ChecksumSHA256\": \"${PART_CHKSUM}\", \"PartNumber\": ${idx}},"
	fi
done

	for i := range key {
		key[i] = byte(i)
	}
	for i, etag := range sealUnsealETagTests {
		tag, err := hex.DecodeString(etag)
		if err != nil {
			t.Errorf("Test %d: failed to decode etag: %s", i, err)
		}
		sealedETag := key.SealETag(tag)
		unsealedETag, err := key.UnsealETag(sealedETag)
		if err != nil {
			t.Errorf("Test %d: failed to decrypt etag: %s", i, err)
		}
		if !bytes.Equal(unsealedETag, tag) {

		}
		if _, err := strconv.ParseInt(object.ETag[i+1:], 10, 32); err != nil {
			return "", errObjectTampered
		}
		return object.ETag, nil
	}

	etag, err := hex.DecodeString(object.ETag)
	if err != nil {
		return "", err
	}
	etag, err = key.UnsealETag(etag)
	if err != nil {
		return "", err
	}
	return hex.EncodeToString(etag), nil
}