*/
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. */

        assertNotNull(dataMap);
        assertTrue(dataMap.get("tags") instanceof List);
        @SuppressWarnings("unchecked")
        List<String> tags = (List<String>) dataMap.get("tags");
        assertEquals(3, tags.size());
        assertEquals("tag1", tags.get(0));
        assertEquals("tag2", tags.get(1));
        assertEquals("tag3", tags.get(2));
    }

        .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}.

///

from enum import Enum

from fastapi import FastAPI

app = FastAPI()


class Tags(Enum):
    items = "items"
    users = "users"


@app.get("/items/", tags=[Tags.items])
async def get_items():
    return ["Portal gun", "Plumbus"]


@app.get("/users/", tags=[Tags.users])
async def read_users():

)

// 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 {

			return err
		}
	}
	return nil
}

// TestTags tests if the object tags satisfy the Filter tags requirement,
// it returns true if there is no tags in the underlying Filter.
func (f *Filter) TestTags(userTags string) bool {
	if f.cachedTags == nil {
		cached := make(map[string]string)
		for _, t := range append(f.And.Tags, f.Tag) {
			if !t.IsEmpty() {
				cached[t.Key] = t.Value
			}
		}

<%@taglib prefix="c" uri="jakarta.tags.core"%><%--
 --%><%@taglib prefix="fmt" uri="jakarta.tags.fmt"%><%--
 --%><%@taglib prefix="fn" uri="jakarta.tags.functions" %><%--
 --%><%@taglib prefix="la" uri="http://lastaflute.org/latags" %><%--
 --%><%@taglib prefix="f" uri="http://lastaflute.org/functions" %><%--
 --%><%@taglib prefix="fe" uri="fess.tags.functions" %><%--