* {@return the identifier of the artifact}
     */
    @Nonnull
    String getArtifactId();

    /**
     * Returns the classifier of the artifact.
     *
     * @return the classifier or an empty string if none, never {@code null}
     */
    @Nonnull
    String getClassifier();

    /**
     * {@return the specific version, range of versions or meta-version of the artifact}

    "path,expected_status,expected_response",
    [
        ("/items", 200, {"q": None, "skip": 0, "limit": 100}),
        ("/items?q=foo", 200, {"q": "foo", "skip": 0, "limit": 100}),
        ("/items?q=foo&skip=5", 200, {"q": "foo", "skip": 5, "limit": 100}),
        ("/items?q=foo&skip=5&limit=30", 200, {"q": "foo", "skip": 5, "limit": 30}),
        ("/users", 200, {"q": None, "skip": 0, "limit": 100}),
    ],
)

<li>Current HEAD Piper Changelist, if any: cl/${KOKORO_PIPER_CHANGELIST:-not available}</li>
<li>Pull Request Number, if any: ${KOKORO_GITHUB_PULL_REQUEST_NUMBER_tensorflow:- none}</li>
<li>Pull Request Link, if any: <a href="$KOKORO_GITHUB_PULL_REQUEST_URL_tensorflow">${KOKORO_GITHUB_PULL_REQUEST_URL_tensorflow:-none}</a></li>
<li>Commit: $KOKORO_GIT_COMMIT_tensorflow</li>
</ul>
<h2>Googlers-Only Links</h2>
<ul>

Zum Beispiel deklariert das obige Modell ein JSON "`object`" (oder Python-`dict`) wie dieses:

```JSON
{
    "name": "Foo",
    "description": "An optional description",
    "price": 45.2,
    "tax": 3.5
}
```

Da `description` und `tax` optional sind (mit `None` als Defaultwert), wäre folgendes JSON "`object`" auch gültig:

Por exemplo, o modelo acima declara um JSON "`object`" (ou `dict` no Python) como esse:

```JSON
{
    "name": "Foo",
    "description": "Uma descrição opcional",
    "price": 45.2,
    "tax": 3.5
}
```

...como `description` e `tax` são opcionais (Com um valor padrão de `None`), esse JSON "`object`" também é válido:

```JSON
{

    "path,expected_status,expected_response",
    [
        ("/items", 200, {"q": None, "skip": 0, "limit": 100}),
        ("/items?q=foo", 200, {"q": "foo", "skip": 0, "limit": 100}),
        ("/items?q=foo&skip=5", 200, {"q": "foo", "skip": 5, "limit": 100}),
        ("/items?q=foo&skip=5&limit=30", 200, {"q": "foo", "skip": 5, "limit": 30}),
        ("/users", 200, {"q": None, "skip": 0, "limit": 100}),
    ],
)

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):

//// tab | Python 3.10+

```Python hl_lines="7"
{!> ../../docs_src/query_params/tutorial002_py310.py!}
```

////

//// tab | Python 3.8+

```Python hl_lines="9"
{!> ../../docs_src/query_params/tutorial002.py!}
```

////

Nesse caso, o parâmetro da função `q` será opcional, e `None` será o padrão.

/// check | "Verificar"

    response = client.get("/items/foo?needy=very")
    assert response.status_code == 200
    assert response.json() == {
        "item_id": "foo",
        "needy": "very",
        "skip": 0,
        "limit": None,
    }


@needs_py310
def test_foo_no_needy(client: TestClient):
    response = client.get("/items/foo?skip=a&limit=b")
    assert response.status_code == 422
    assert response.json() == IsDict(
        {

    "path,expected_status,expected_response",
    [
        ("/items", 200, {"q": None, "skip": 0, "limit": 100}),
        ("/items?q=foo", 200, {"q": "foo", "skip": 0, "limit": 100}),
        ("/items?q=foo&skip=5", 200, {"q": "foo", "skip": 5, "limit": 100}),
        ("/items?q=foo&skip=5&limit=30", 200, {"q": "foo", "skip": 5, "limit": 30}),
        ("/users", 200, {"q": None, "skip": 0, "limit": 100}),
    ],
)