checkNotDone();
      digest.update(bytes);
    }

    private void checkNotDone() {
      checkState(!done, "Cannot re-use a Hasher after calling hash() on it");
    }

    @Override
    public HashCode hash() {
      checkNotDone();
      done = true;
      return (bytes == digest.getDigestLength())
          ? HashCode.fromBytesNoCopy(digest.digest())

## Paramètres optionnels

De la même façon, vous pouvez définir des paramètres de requête comme optionnels, en leur donnant comme valeur par défaut `None` :

{* ../../docs_src/query_params/tutorial002.py hl[9] *}

Ici, le paramètre `q` sera optionnel, et aura `None` comme valeur par défaut.

/// check | "Remarque"

app = FastAPI()


class Item(BaseModel):
    name: str
    price: float
    is_offer: Union[bool, None] = None


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}


@app.put("/items/{item_id}")
def update_item(item_id: int, item: Item):

    client = TestClient(app)
    return client


@needs_py39
@pytest.mark.parametrize(
    "path,headers,expected_status,expected_response",
    [
        ("/items", None, 200, {"X-Token values": None}),
        ("/items", {"x-token": "foo"}, 200, {"X-Token values": ["foo"]}),
        # TODO: fix this, is it a bug?

    assertEquals(4, diff.evictionCount());

    assertEquals(new CacheStats(0, 0, 0, 0, 0, 0), one.minus(two));
  }

  public void testPlus() {
    CacheStats one = new CacheStats(11, 13, 15, 13, 11, 9);
    CacheStats two = new CacheStats(53, 47, 41, 39, 37, 35);

    CacheStats sum = two.plus(one);
    assertEquals(124, sum.requestCount());
    assertEquals(64, sum.hitCount());

    assertMultimapEquals(ImmutableSetMultimap.of("one", 1), "one", 1);
    assertMultimapEquals(ImmutableSetMultimap.of("one", 1, "two", 2), "one", 1, "two", 2);
    assertMultimapEquals(
        ImmutableSetMultimap.of("one", 1, "two", 2, "three", 3), "one", 1, "two", 2, "three", 3);
    assertMultimapEquals(
        ImmutableSetMultimap.of("one", 1, "two", 2, "three", 3, "four", 4),
        "one",
        1,
        "two",
        2,

👉 🚫 🚫 **FastAPI**, ⚫️ 🍕 🇺🇸🔍 🛠️.

///

## 📦 📁 📂

👆 💪 ⚒ 📁 📦 ⚙️ 🐩 🆎 ✍ & ⚒ 🔢 💲 `None`:

//// tab | 🐍 3️⃣.6️⃣ & 🔛

```Python hl_lines="9  17"
{!> ../../docs_src/request_files/tutorial001_02.py!}
```

////

//// tab | 🐍 3️⃣.1️⃣0️⃣ & 🔛

    app,
    create_access_token,
    fake_users_db,
    get_password_hash,
    verify_password,
)

client = TestClient(app)


def get_access_token(username="johndoe", password="secret", scope=None):
    data = {"username": username, "password": password}
    if scope:
        data["scope"] = scope
    response = client.post("/token", data=data)
    content = response.json()

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = {ZERO, ONE})
  public void testRetainAll_subset() {
    expectReturnsTrue(nonEmptyProperSubset);
    expectContents(nonEmptyProperSubset.toRetain);
  }

  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = {ZERO, ONE})
  public void testRetainAll_subsetUnsupported() {
    expectThrows(nonEmptyProperSubset);

	},
	{ // 2. replication status for one target
		name:      "replication status for one target",
		rs:        ReplicationState{ReplicationStatusInternal: "arn1=PENDING;", Targets: map[string]replication.StatusType{"arn1": "PENDING"}},
		expStatus: replication.Pending,
	},
	{ // 3. replication status for one target - incorrect format
		name:      "replication status for one target",