final class Internal {

  /**
   * Returns the number of nanoseconds of the given duration without throwing or overflowing.
   *
   * <p>Instead of throwing {@link ArithmeticException}, this method silently saturates to either
   * {@link Long#MAX_VALUE} or {@link Long#MIN_VALUE}. This behavior can be useful when decomposing
   * a duration in order to call a legacy API which requires a {@code long, TimeUnit} pair.
   */

但 FastAPI 还可以使用数据类（<a href="https://docs.python.org/3/library/dataclasses.html" class="external-link" target="_blank">`dataclasses`</a>）：

{* ../../docs_src/dataclasses_/tutorial001.py hl[1,7:12,19:20] *}

这还是借助于 **Pydantic** 及其<a href="https://pydantic-docs.helpmanual.io/usage/dataclasses/#use-of-stdlib-dataclasses-with-basemodel" class="external-link" target="_blank">内置的 `dataclasses`</a>。

/// info | Información

Esto requiere instalar `orjson`, por ejemplo, con `pip install orjson`.

///

### `UJSONResponse` { #ujsonresponse }

Un response JSON alternativo usando <a href="https://github.com/ultrajson/ultrajson" class="external-link" target="_blank">`ujson`</a>.

/// info | Información

打开浏览器访问 <a href="http://127.0.0.1:8000" class="external-link" target="_blank">http://127.0.0.1:8000</a>。

你将看到如下的 JSON 响应：

```JSON
{"message": "Hello World"}
```

### 交互式 API 文档

跳转到 <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>。

你将会看到自动生成的交互式 API 文档（由 <a href="https://github.com/swagger-api/swagger-ui" class="external-link" target="_blank">Swagger UI</a> 提供）：

      if (testerSuite.countTestCases() > 0) {
        suite.addTest(testerSuite);
      }
    }
    return suite;
  }

  /** Throw {@link IllegalStateException} if {@link #createTestSuite()} can't be called yet. */
  protected void checkCanCreate() {
    if (subjectGenerator == null) {
      throw new IllegalStateException("Call using() before createTestSuite().");
    }

Para hacerlo, usa la anotación de tipos estándar de Python <a href="https://docs.python.org/3/library/typing.html#typing.Union" class="external-link" target="_blank">`typing.Union`</a>:

/// note | Nota

También puedes declarar responses adicionales con sus modelos, códigos de estado, etc.

Hay un capítulo entero en la documentación sobre ello, puedes leerlo en [Responses Adicionales en OpenAPI](additional-responses.md){.internal-link target=_blank}.

## OpenAPI Extra { #openapi-extra }

Você também pode declarar respostas adicionais, com seus modelos, códigos de status, etc.

Existe um capítulo inteiro da nossa documentação sobre isso, você pode ler em [Retornos Adicionais no OpenAPI](additional-responses.md){.internal-link target=_blank}.

## Extras do OpenAPI { #openapi-extra }

Как вы видели в предыдущей главе о [Концепциях деплоя](concepts.md){.internal-link target=_blank}, существует несколько стратегий.

Здесь я покажу, как использовать **Uvicorn** с **воркер-процессами** через команду `fastapi` или напрямую через команду `uvicorn`.

/// info | Информация

import java.security.NoSuchAlgorithmException;
import java.util.Random;
import org.jspecify.annotations.NullUnmarked;

/**
 * Benchmarks for comparing {@link MessageDigest}s and {@link com.google.common.hash.HashFunction}s
 * that wrap {@link MessageDigest}s.
 *
 * <p>Parameters for the benchmark are:
 *
 * <ul>
 *   <li>size: The length of the byte array to hash.