*
   * <p>If the mapped keys or values contain duplicates (according to {@link
   * Object#equals(Object)}), an {@code IllegalArgumentException} is thrown when the collection
   * operation is performed. (This differs from the {@code Collector} returned by {@link
   * Collectors#toMap(Function, Function)}, which throws an {@code IllegalStateException}.)
   *
   * @since 21.0
   */

  // unrunnable.
  for (auto it : graph->sessions) {
    mutex_lock session_lock(it.first->mu);
    if (it.first->last_num_graph_nodes > op.node.id()) {
      it.second = strings::StrCat(
          "Operation '", op.node.DebugString(), "' was changed by ",
          mutation_type,
          " after it was run by a session. This mutation will have no effect, "
          "and will trigger an error in the future. Either don't modify "

                            "content": {"application/json": {"schema": {}}},
                        },
                        "404": {"description": "Not found"},
                        "403": {"description": "Operation forbidden"},
                        "422": {
                            "description": "Validation Error",
                            "content": {
                                "application/json": {

```Python
some_variable: PlaneItem | CarItem
```

Aber wenn wir das in der Zuweisung `response_model=PlaneItem | CarItem` machen, erhalten wir eine Fehlermeldung, da Python versucht, eine **ungültige Operation** zwischen `PlaneItem` und `CarItem` durchzuführen, statt es als Typannotation zu interpretieren.

## Listen von Modellen

Genauso können Sie eine Response deklarieren, die eine Liste von Objekten ist.

///

### 태그 사용

`tags` 매개변수를 *경로 작동* 및 `APIRouter`와 함께 사용하여 태그에 할당할 수 있습니다:

```Python hl_lines="21  26"
{!../../docs_src/metadata/tutorial004.py!}
```

/// info

태그에 대한 자세한 내용은 [경로 작동 구성](path-operation-configuration.md#tags){.internal-link target=_blank}에서 읽어보세요.

///

### 문서 확인

이제 문서를 확인하면 모든 추가 메타데이터가 표시됩니다:

<img src="/img/tutorial/metadata/image02.png">

### 태그 순서

	toNames := func(delObjs []delObj) []ObjectToDelete {
		objs := make([]ObjectToDelete, len(delObjs))
		for i, obj := range delObjs {
			objs[i] = obj.object
		}
		return objs
	}

	// The result of delete operation on all passed objects
	delErrs := make([]error, len(objects))

	// The result of delete objects
	delObjects := make([]DeletedObject, len(objects))

	// A map between a set and its associated objects

    return invertedMultimap;
  }

  /**
   * Guaranteed to throw an exception and leave the multimap unmodified.
   *
   * @throws UnsupportedOperationException always
   * @deprecated Unsupported operation.
   */
  @CanIgnoreReturnValue
  @Deprecated
  @Override
  @DoNotCall("Always throws UnsupportedOperationException")
  public final ImmutableSet<V> removeAll(@CheckForNull Object key) {

    return invertedMultimap;
  }

  /**
   * Guaranteed to throw an exception and leave the multimap unmodified.
   *
   * @throws UnsupportedOperationException always
   * @deprecated Unsupported operation.
   */
  @CanIgnoreReturnValue
  @Deprecated
  @Override
  @DoNotCall("Always throws UnsupportedOperationException")
  public final ImmutableSet<V> removeAll(@CheckForNull Object key) {

...경로는 다음과 같습니다:

```
/items/foo
```

/// info | "정보"

"경로"는 일반적으로 "엔드포인트" 또는 "라우트"라고도 불립니다.

///

API를 설계할 때 "경로"는 "관심사"와 "리소스"를 분리하기 위한 주요한 방법입니다.

#### 작동

"작동(Operation)"은 HTTP "메소드" 중 하나를 나타냅니다.

다음 중 하나이며:

* `POST`
* `GET`
* `PUT`
* `DELETE`

...흔히 사용되지 않는 것들도 있습니다:

* `OPTIONS`
* `HEAD`
* `PATCH`
* `TRACE`

                    to:
                      description: Optional.
                      items:
                        properties:
                          operation:
                            description: Operation specifies the operation of a request.
                            properties:
                              hosts:
                                description: Optional.