protected void initMapWithNullValue() {
    resetMap(createArrayWithNullValue());
  }

  /**
   * Equivalent to {@link #expectMissingKeys(Object[]) expectMissingKeys} {@code (null)} except that
   * the call to {@code contains(null)} is permitted to throw a {@code NullPointerException}.
   *
   * @param message message to use upon assertion failure
   */
  protected void expectNullKeyMissingWhenNullKeysUnsupported(String message) {

- <a href="https://jinja.palletsprojects.com" target="_blank"><code>jinja2</code></a> - 使用預設的模板配置時必須安裝。
- <a href="https://github.com/Kludex/python-multipart" target="_blank"><code>python-multipart</code></a> - 需要使用 `request.form()` 對表單進行<abbr title="轉換來自表單的 HTTP 請求到 Python 資料型別"> "解析" </abbr>時安裝。

Bien que dans FastAPI, il est facultatif, et est utilisé principalement pour définir les en-têtes, les cookies, et les codes de statut alternatifs.

///

### <a href="https://moltenframework.com/" class="external-link" target="_blank">Molten</a>

///

## Write the callback documentation code { #write-the-callback-documentation-code }

This code won't be executed in your app, we only need it to *document* how that *external API* should look like.

But, you already know how to easily create automatic documentation for an API with **FastAPI**.

* <a href="https://github.com/JoshData/python-email-validator" target="_blank"><code>email-validator</code></a> - para validación de correos electrónicos.

Usadas por Starlette:

* <a href="https://www.python-httpx.org" target="_blank"><code>httpx</code></a> - Requerido si deseas usar el `TestClient`.
* <a href="https://jinja.palletsprojects.com" target="_blank"><code>jinja2</code></a> - Requerido si deseas usar la configuración de plantilla predeterminada.

* <a href="https://github.com/JoshData/python-email-validator" target="_blank"><code>email-validator</code></a> - para validação de email.

Utilizado pelo Starlette:

* <a href="https://www.python-httpx.org" target="_blank"><code>httpx</code></a> - Obrigatório caso você queira utilizar o `TestClient`.
* <a href="https://jinja.palletsprojects.com" target="_blank"><code>jinja2</code></a> - Obrigatório se você quer utilizar a configuração padrão de templates.

Außerdem dienen diese als zukünftige Referenz.

Dadurch können Sie jederzeit  zurückkommen und sehen genau das, was Sie benötigen.

## Den Code ausführen

Alle Codeblöcke können kopiert und direkt verwendet werden (da es sich um getestete Python-Dateien handelt).

Um eines der Beispiele auszuführen, kopieren Sie den Code in eine Datei `main.py`, und starten Sie `uvicorn` mit:

<div class="termy">

```console
$ uvicorn main:app --reload

Таким чином, значення `0.5` буде допустимим. Але `0.0` або `0` — ні.

Те саме стосується <abbr title="less than (менше ніж)"><code>lt</code></abbr>.

Modern versions of Python have support for **"asynchronous code"** using something called **"coroutines"**, with **`async` and `await`** syntax.

Let's see that phrase by parts in the sections below:

* **Asynchronous Code**
* **`async` and `await`**
* **Coroutines**

## Asynchronous Code { #asynchronous-code }

    end

    rect rgba(0, 255, 0, .1)
        code ->> function: say_hi(name="Rick")
        function ->> execute: ejecutar código de la función
        execute ->> code: devolver el resultado
    end

    rect rgba(0, 255, 0, .1)
        code ->> function: say_hi(name="Rick", salutation="Mr.")
        function ->> execute: ejecutar código de la función