@app.put("/items/{item_id}")
async def update_item(
    item_id: int,
    item: Annotated[
        Item,
        Body(
            examples=[
                {
                    "name": "Foo",
                    "description": "A very nice Item",
                    "price": 35.4,
                    "tax": 3.2,
                }
            ],
        ),
    ],
):

    assertTrue(set.isEmpty());
    set.add(new Derived("foo"));
    set.add(new Derived("bar"));
    assertThat(set).containsExactly(new Derived("bar"), new Derived("foo")).inOrder();
  }

  public void testNewTreeSetEmptyNonGeneric() {
    TreeSet<LegacyComparable> set = Sets.newTreeSet();
    assertTrue(set.isEmpty());
    set.add(new LegacyComparable("foo"));
    set.add(new LegacyComparable("bar"));
    assertThat(set)

Mit diesen Ideen kann JWT für weitaus anspruchsvollere Szenarien verwendet werden.

In diesen Fällen könnten mehrere dieser Entitäten die gleiche ID haben, sagen wir `foo` (ein Benutzer `foo`, ein Auto `foo` und ein Blog-Beitrag `foo`).

@app.put("/items/{item_id}")
async def update_item(
    item_id: int,
    item: Annotated[
        Item,
        Body(
            examples=[
                {
                    "name": "Foo",
                    "description": "A very nice Item",
                    "price": 35.4,
                    "tax": 3.2,
                }
            ],
        ),
    ],
):

```Python hl_lines="9"
{!../../docs_src/header_params/tutorial003.py!}
```

다음과 같은 두 개의 HTTP 헤더를 전송하여 해당 *경로* 와 통신할 경우:

```
X-Token: foo
X-Token: bar
```

응답은 다음과 같습니다:

```JSON
{
    "X-Token values": [
        "bar",
        "foo"
    ]
}
```

## 요약

`Header`는 `Query`, `Path`, `Cookie`와 동일한 패턴을 사용하여 선언합니다.

from typing import Union

from fastapi import Depends, FastAPI

app = FastAPI()


fake_items_db = [{"item_name": "Foo"}, {"item_name": "Bar"}, {"item_name": "Baz"}]


class CommonQueryParams:
    def __init__(self, q: Union[str, None] = None, skip: int = 0, limit: int = 100):
        self.q = q
        self.skip = skip
        self.limit = limit


@app.get("/items/")
async def read_items(commons: CommonQueryParams = Depends()):

    builder.put("foo", 2);
    assertMapEquals(builder.buildOrThrow(), "foo", 2);
  }

  public void testBuilderPutImmutableEntryWithNullKeyFailsAtomically() {
    Builder<String, Integer> builder = new Builder<>();
    assertThrows(NullPointerException.class, () -> builder.put(immutableEntry((String) null, 1)));
    builder.put("foo", 2);
    assertMapEquals(builder.buildOrThrow(), "foo", 2);

    val url = parse("http://host/?foo[]=1&foo[]=2&foo[]=3")
    assertThat(url.querySize).isEqualTo(3)
    assertThat(url.queryParameterNames).isEqualTo(setOf("foo[]"))
    assertThat(url.queryParameterValue(0)).isEqualTo("1")
    assertThat(url.queryParameterValue(1)).isEqualTo("2")
    assertThat(url.queryParameterValue(2)).isEqualTo("3")
    assertThat(url.queryParameterValues("foo[]")).containsExactly("1", "2", "3")
  }

          @Override
          protected String serviceName() {
            return "Foo";
          }
        };
    TimeoutException e =
        assertThrows(
            TimeoutException.class, () -> service.startAsync().awaitRunning(1, MILLISECONDS));
    assertThat(e)
        .hasMessageThat()
        .isEqualTo("Timed out waiting for Foo [STARTING] to reach the RUNNING state.");
  }

```

////

Если вы взаимодействуете с этой *операцией пути*, отправляя два HTTP-заголовка, таких как:

```
X-Token: foo
X-Token: bar
```

Ответ был бы таким:

```JSON
{
    "X-Token values": [
        "bar",
        "foo"
    ]
}
```

## Резюме

Объявляйте заголовки с помощью `Header`, используя тот же общий шаблон, как при `Query`, `Path` и `Cookie`.