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

		// This should fail even without quorum issues, but with quorum failure
		// we can't verify the ETag at all.
		opts := ObjectOptions{
			UserDefined: map[string]string{
				xhttp.IfMatch: "wrong-etag-12345",
			},
			HasIfMatch: true,
			CheckPrecondFn: func(oi ObjectInfo) bool {
				// Precondition fails if ETags don't match
				return oi.ETag != "wrong-etag-12345"
			},
		}

	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

 */
internal sealed class Tags {
  /**
   * Returns a tags instance that maps [key] to [value]. If [value] is null, this returns a tags
   * instance that does not have any mapping for [key].
   */
  abstract fun <T : Any> plus(
    key: KClass<T>,
    value: T?,
  ): Tags

  abstract operator fun <T : Any> get(key: KClass<T>): T?
}

/** An empty tags. This is always the tail of a [LinkedTags] chain. */

./mc put --quiet README.md sitea/testbucket/file
etag1=$(./mc cat sitea/testbucket/file | md5sum --tag | awk {'print $4'})

./mc cp --quiet --storage-class "STANDARD" sitea/testbucket/file sitea/testbucket/file
etag2=$(./mc cat sitea/testbucket/file | md5sum --tag | awk {'print $4'})
if [ $etag1 != $etag2 ]; then
	echo "expected $etag1, got $etag2"
	exit 1
fi

echo "SUCCESS:"

	}

	// Set tag count if object has tags
	if len(objInfo.UserTags) > 0 {
		tags, _ := tags.ParseObjectTags(objInfo.UserTags)
		if tags != nil && tags.Count() > 0 {
			w.Header()[xhttp.AmzTagCount] = []string{strconv.Itoa(tags.Count())}
			if opts.Tagging {
				// This is MinIO only extension to return back tags along with the count.
				w.Header()[xhttp.AmzObjectTagging] = []string{objInfo.UserTags}

        .plus(Boolean::class, null)
    assertThat(tags).isEqualTo(EmptyTags)
    assertThat(tags.toString()).isEqualTo("{}")
  }

  @Test
  fun removeAbsentFromEmpty() {
    val tags = EmptyTags.plus(String::class, null)
    assertThat(tags).isEqualTo(EmptyTags)
    assertThat(tags.toString()).isEqualTo("{}")
  }

  @Test
  fun removeAbsentFromNonEmpty() {
    val tags =
      EmptyTags

	defer r.Unlock()
	// Search of tag key already exists in tags
	var updated bool
	for _, tag := range r.tags {
		if tag.Key == key {
			tag.Val = val
			updated = true
			break
		}
	}
	if !updated {
		// Append to the end of tags list
		r.tags = append(r.tags, KeyVal{key, val})
	}
	return r
}

// GetTags - returns the user defined tags
func (r *ReqInfo) GetTags() []KeyVal {
	if r == nil {

                                    "required": ["name", "tags"],
                                    "type": "object",
                                    "properties": {
                                        "name": {"title": "Name", "type": "string"},
                                        "tags": {
                                            "title": "Tags",
                                            "type": "array",

/// tip

You don't have to add metadata for all the tags that you use.

///

### Use your tags { #use-your-tags }

Use the `tags` parameter with your *path operations* (and `APIRouter`s) to assign them to different tags:

{* ../../docs_src/metadata/tutorial004_py39.py hl[21,26] *}

/// info

Read more about tags in [Path Operation Configuration](path-operation-configuration.md#tags){.internal-link target=_blank}.

///