Ao ter o tipo como `int | None`, o SQLModel saberá que essa coluna deve ser um `INTEGER` no banco de dados SQL e que ela deve ser `NULLABLE`.

* `Field(index=True)` informa ao SQLModel que ele deve criar um **índice SQL** para essa coluna, o que permitirá buscas mais rápidas no banco de dados ao ler dados filtrados por essa coluna.

    Al tener el tipo como `int | None`, SQLModel sabrá que esta columna debe ser un `INTEGER` en la base de datos SQL y que debe ser `NULLABLE`.

* `Field(index=True)` le dice a SQLModel que debe crear un **índice SQL** para esta columna, lo que permitirá búsquedas más rápidas en la base de datos cuando se lean datos filtrados por esta columna.

* `Field(primary_key=True)`는 SQLModel에 `id`가 SQL 데이터베이스의 **기본 키**임을 알려줍니다 (SQL 기본 키에 대한 자세한 내용은 SQLModel 문서를 참고하세요).

    `int | None` 유형으로 설정하면, SQLModel은 해당 열이 SQL 데이터베이스에서 `INTEGER` 유형이며 `NULLABLE` 값이어야 한다는 것을 알 수 있습니다.

* `Field(index=True)`는 SQLModel에 해당 열에 대해 **SQL 인덱스**를 생성하도록 지시합니다. 이를 통해 데이터베이스에서 이 열으로 필터링된 데이터를 읽을 때 더 빠르게 조회할 수 있습니다.

    is a view of what created it, we use _as_.
 *  Fix: Permit response codes of zero for compatibility with OkHttp 3.x.
 *  Fix: Change the return type of `MockWebServer.takeRequest()` to be nullable.
 *  Fix: Make `Call.clone()` public to Kotlin callers.


## Version 4.0.0-RC1

_2019-06-03_

 *  First stable preview of OkHttp 4.


## Version 3.x

- CRDs: For structural schemas, non-nullable null map fields will now be dropped and defaulted if a default is available. null items in the list will continue being preserved, and fail validation if not nullable. ([#95423](https://github.com/kubernetes/kubernetes/pull/95423), [@apelisse](https://github.com/apelisse)) [SIG API Machinery]

But we want to be able to parameterize that fixed content.

## A "callable" instance { #a-callable-instance }

In Python there's a way to make an instance of a class a "callable".

Not the class itself (which is already a callable), but an instance of that class.

To do that, we declare a method `__call__`:

{* ../../docs_src/dependencies/tutorial011_an_py39.py hl[12] *}

- Filter published OpenAPI schema by making nullable, required fields non-required in order to avoid kubectl to wrongly reject null values. ([#85722](https://github.com/kubernetes/kubernetes/pull/85722), [@sttts](https://github.com/sttts))

Pero queremos poder parametrizar ese contenido fijo.

## Una *instance* "callable"

En Python hay una forma de hacer que una instance de una clase sea un "callable".

No la clase en sí (que ya es un callable), sino una instance de esa clase.

Para hacer eso, declaramos un método `__call__`:

{* ../../docs_src/dependencies/tutorial011_an_py39.py hl[12] *}

- Filter published OpenAPI schema by making nullable, required fields non-required in order to avoid kubectl to wrongly reject null values. ([#85722](https://github.com/kubernetes/kubernetes/pull/85722), [@sttts](https://github.com/sttts)) [SIG API Machinery]

    // HcHttpClient.AUTHENTICATIONS_PROPERTY,
    // basicAuthList.toArray(new Authentication[basicAuthList.size()]));
    //
    // List<Callable<ResponseData>> list =
    // new ArrayList<Callable<ResponseData>>();
    // for (int i = 0; i < 100; i++) {
    // list.add(new Callable<ResponseData>() {
    // public ResponseData call() throws Exception {
    // String[] urls =
    // new String[] {
    // "http://.../",