*
   * <p><b>Note:</b> this method does not return the number of <i>distinct elements</i> in the
   * multiset, which is given by {@code entrySet().size()}.
   */
  @Override
  int size();

  /**
   * Returns the number of occurrences of an element in this multiset (the <i>count</i> of the
   * element). Note that for an {@link Object#equals}-based multiset, this gives the same result as

        git diff --diff-filter ACMRT --name-only pull_branch^ pull_branch > $BATS_FILE_TMPDIR/changed_files
    else
        # If the branch is not present, then diff against origin/master
        git diff --diff-filter ACMRT --name-only origin/master > $BATS_FILE_TMPDIR/changed_files
    fi
}

# Note: this is excluded on the full code base, since any submitted code must
# have passed Google's internal style guidelines.

```

Note que substituímos o valor padrão de `None` para `Query(default=None)`, o primeiro parâmetro de `Query` serve para o mesmo propósito: definir o valor padrão do parâmetro.

Então:

```Python
q: Union[str, None] = Query(default=None)
```

...Torna o parâmetro opcional, da mesma maneira que:

```Python
q: Union[str, None] = None
```

## Importe `Field`

Primeiro, você tem que importá-lo:

```Python hl_lines="4"
{!../../../docs_src/body_fields/tutorial001.py!}
```

!!! warning "Aviso"
    Note que `Field` é importado diretamente do `pydantic`, não do `fastapi` como todo o resto (`Query`, `Path`, `Body`, etc).

## Declare atributos do modelo

Você pode então utilizar `Field` com atributos do modelo:

<img src="/img/tutorial/response-status-code/image01.png">

!!! note "Nota"
    Alguns códigos de resposta (consulte a próxima seção) indicam que a resposta não possui um corpo.

    O FastAPI sabe disso e produzirá documentos OpenAPI informando que não há corpo de resposta.

## Sobre os códigos de status HTTP

!!! note "Nota"
    Se você já sabe o que são códigos de status HTTP, pule para a próxima seção.

        git diff --diff-filter ACMRT --name-only pull_branch^ pull_branch > $BATS_FILE_TMPDIR/changed_files
    else
        # If the branch is not present, then diff against origin/master
        git diff --diff-filter ACMRT --name-only origin/master > $BATS_FILE_TMPDIR/changed_files
    fi
}

# Note: this is excluded on the full code base, since any submitted code must
# have passed Google's internal style guidelines.

	  createdBefore: "date" # match objects created before "date"

	  ## NOTE: tags are not supported when "source" is remote.
	  # tags:
	  #   - key: "name"
	  #     value: "pick*" # match objects with tag 'name', with all values starting with 'pick'

	  ## NOTE: metadata filter not supported when "source" is non MinIO.
	  # metadata:
	  #   - key: "content-type"

```

Le paramètre de requête `q` a pour type `Union[str, None]` (ou `str | None` en Python 3.10), signifiant qu'il est de type `str` mais pourrait aussi être égal à `None`, et bien sûr, la valeur par défaut est `None`, donc **FastAPI** saura qu'il n'est pas requis.

!!! note
    **FastAPI** saura que la valeur de `q` n'est pas requise grâce à la valeur par défaut `= None`.

   * {@code SerializableTester} calls with other, GWT-compatible tests.
   *
   * <p>Note that the specified object may not be known by the compiler to be a {@link
   * java.io.Serializable} instance, and is thus declared an {@code Object}. For example, it might
   * be declared as a {@code List}.
   *
   * <p>Note also that serialization is not in general required to return an object that is

⚫️ 🔜:

* 📨 👈 👔 📟 📨.
* 📄 ⚫️ ✅ 🗄 🔗 ( & , 👩‍💻 🔢):

<img src="/img/tutorial/response-status-code/image01.png">

!!! note
    📨 📟 (👀 ⏭ 📄) 🎦 👈 📨 🔨 🚫 ✔️ 💪.

    FastAPI 💭 👉, &amp; 🔜 🏭 🗄 🩺 👈 🇵🇸 📤 🙅‍♂ 📨 💪.

## 🔃 🇺🇸🔍 👔 📟

!!! note
    🚥 👆 ⏪ 💭 ⚫️❔ 🇺🇸🔍 👔 📟, 🚶 ⏭ 📄.

🇺🇸🔍, 👆 📨 🔢 👔 📟 3️⃣ 9️⃣ 🍕 📨.

👫 👔 📟 ✔️ 📛 🔗 🤔 👫, ✋️ ⚠ 🍕 🔢.

📏: