// for more detail.
	tags = append(tags, context.GOOS, context.GOARCH)
	slices.Sort(tags)

	for _, tag := range tags {
		if ctags[tag] {
			key += "," + tag
			ctags[tag] = false
		}
	}
	return key
}

type listImports struct {
	stdPackages []string                     // names, omitting "unsafe", internal, and vendored packages

 */
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. */

			objInfo.Expires = t.UTC()
		}
	}

	// Extract etag from metadata.
	objInfo.ETag = extractETag(fi.Metadata)

	// Add user tags to the object info
	tags := fi.Metadata[xhttp.AmzObjectTagging]
	if len(tags) != 0 {
		objInfo.UserTags = tags
	}

	// Add replication status to the object info
	objInfo.ReplicationStatusInternal = fi.ReplicationState.ReplicationStatusInternal

		t.Fatalf("Blog should has three tags after Append")
	}

	if count := DB.Model(&blog).Association("Tags").Count(); count != 3 {
		t.Fatalf("Blog should has 3 tags after Append, got %v", count)
	}

	var tags []Tag
	DB.Model(&blog).Association("Tags").Find(&tags)
	if !compareTags(tags, []string{"tag1", "tag2", "tag3"}) {
		t.Fatalf("Should find 3 tags")
	}

	var blog1 Blog
	DB.Preload("Tags").Find(&blog1)

	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 {

        .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

                                    "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}.

///

// S3 singlepart ETags. It returns nil if the list of
// ETags is empty.
//
// Any encrypted or multipart ETag will be ignored and not
// used to compute the returned ETag.
func Multipart(etags ...ETag) ETag {
	if len(etags) == 0 {
		return nil
	}

	var n int64
	h := md5.New()
	for _, etag := range etags {
		if !etag.IsMultipart() && !etag.IsEncrypted() {

)

// And - a tag to combine a prefix and multiple tags for replication configuration rule.
type And struct {
	XMLName xml.Name `xml:"And" json:"And"`
	Prefix  string   `xml:"Prefix,omitempty" json:"Prefix,omitempty"`
	Tags    []Tag    `xml:"Tag,omitempty" json:"Tag,omitempty"`
}

var errDuplicateTagKey = Errorf("Duplicate Tag Keys are not allowed")

// isEmpty returns true if Tags field is null
func (a And) isEmpty() bool {