OkHttpClient
        .Builder()
        .trustMockServer()
        .dispatcher(Dispatcher(newVirtualThreadPerTaskExecutor()))
        .build()

    executor = newVirtualThreadPerTaskExecutor()

    // Capture non-deterministic but probable sysout warnings of pinned threads
    // https://docs.oracle.com/en/java/javase/21/core/virtual-threads.html
    System.setOut(PrintStream(capturedOut))
  }

  @AfterEach
  fun checkForPinning() {

   *
   * <p>If the function throws an exception, that exception is used as the result of the derived
   * {@code ClosingFuture}. But if the exception is thrown after the function creates a {@code
   * ClosingFuture}, then none of the closeable objects in that {@code ClosingFuture} will be
   * closed.
   *
   * <p>Usage guidelines for this method:
   *
   * <ul>

          /*
           * standardToArray returns `@Nullable Object[]` rather than `Object[]` but only because it
           * can be used with collections that may contain null. This collection is a collection of
           * non-null Entry objects (Entry objects that might contain null values but are not
           * themselves null), so we can treat it as a plain `Object[]`.
           */
          @SuppressWarnings("nullness")

        // Under some edge cases (such as the proxy of JDK types serialized and then deserialized)
        // the proxy type may not be the same.
        // We first check isProxyClass() so that the common case of comparing with non-proxy objects
        // is efficient.
        || (Proxy.isProxyClass(arg.getClass())
            && Arrays.equals(arg.getClass().getInterfaces(), proxyClass.getInterfaces()));
  }

     * Retrieves the configuration for the specified field name.
     *
     * @param fieldName the name of the field to get configuration for
     * @return an OptionalThing containing the Config if the field exists and has a non-blank value,
     *         otherwise an empty OptionalThing
     */
    public OptionalThing<Config> getConfig(final String fieldName) {
        final String value = params.get(fieldName);

              <outputFilename>maven-skinny-bom.xml</outputFilename>
              <reactorDependencies>REACTOR</reactorDependencies>
              <transitiveDependencies>NONE</transitiveDependencies>
              <usePropertiesForVersion>true</usePropertiesForVersion>
              <attach>true</attach>
            </configuration>
          </execution>
          <execution>

///

## Optional File Upload { #optional-file-upload }

You can make a file optional by using standard type annotations and setting a default value of `None`:

{* ../../docs_src/request_files/tutorial001_02_an_py310.py hl[9,17] *}

## `UploadFile` with Additional Metadata { #uploadfile-with-additional-metadata }

/// note

- 请注意，您必须直接使用 `FileResponse` 返回图像。

///

/// info

- 除非在 `responses` 参数中明确指定不同的媒体类型，否则**FastAPI**将假定响应与主响应类具有相同的媒体类型（默认为` application/json` ）。
- 但是如果您指定了一个自定义响应类，并将 `None `作为其媒体类型，**FastAPI**将使用 `application/json` 作为具有关联模型的任何其他响应。

///

## 组合信息
您还可以联合接收来自多个位置的响应信息，包括 `response_model `、 `status_code` 和 `responses `参数。

Isso não é uma limitação do **FastAPI**, é parte do protocolo HTTP.

///

## Upload de Arquivo Opcional

Você pode tornar um arquivo opcional usando anotações de tipo padrão e definindo um valor padrão de `None`:

{* ../../docs_src/request_files/tutorial001_02_an_py310.py hl[9,17] *}

## `UploadFile` com Metadados Adicionais

Você também pode usar `File()` com `UploadFile`, por exemplo, para definir metadados adicionais:

```

/// tip

آرگومان دوم <a href="https://docs.python.org/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> مقدار پیش‌فرضیه که برمی‌گردونه.

اگه ندی، به‌صورت پیش‌فرض `None` هست، اینجا ما `"World"` رو به‌عنوان مقدار پیش‌فرض گذاشتیم.

///

بعد می‌تونی اون برنامه پایتون رو صدا کنی:

//// tab | لینوکس، مک‌اواس، ویندوز بش

<div class="termy">

```console