try {
        logger.fine("$this starting to accept connections")
        acceptConnections()
      } catch (e: Throwable) {
        logger.log(Level.WARNING, "$this failed unexpectedly", e)
      }

      // Release all sockets and all threads, even if any close fails.
      serverSocket?.closeQuietly()

      val openClientSocket = openClientSockets.iterator()

      return constructor.newInstance();
    } catch (InstantiationException | IllegalAccessException impossible) {
      throw new AssertionError(impossible);
    } catch (InvocationTargetException e) {
      logger.log(Level.WARNING, "Exception while invoking default constructor.", e.getCause());
      return arbitraryConstantInstanceOrNull(type);
    }
  }

  private static <T> @Nullable T arbitraryConstantInstanceOrNull(Class<T> type) {

<img src="/img/tutorial/behind-a-proxy/image02.png">

一切正常。 ✔️

这是因为 FastAPI 在 OpenAPI 里使用 `root_path` 提供的 URL 创建默认 `server`。

## 附加的服务器

/// warning | 警告

此用例较难，可以跳过。

///

默认情况下，**FastAPI** 使用 `root_path` 的链接在 OpenAPI 概图中创建 `server`。

但也可以使用其它备选 `servers`，例如，需要同一个 API 文档与 staging 和生产环境交互。

### Использование менеджеров контекста в зависимостях с `yield` { #using-context-managers-in-dependencies-with-yield }

/// warning | Внимание

Это, более или менее, «продвинутая» идея.

Если вы только начинаете работать с **FastAPI**, то лучше пока пропустить этот пункт.

///

            # (e.g. `TypeAdapter(Annotated[int, Field(alias='b')])`). In some cases, we
            # end up building the type adapter from a model field annotation so we
            # need to ignore the warning:
            if shared.PYDANTIC_VERSION_MINOR_TUPLE >= (2, 12):
                from pydantic.warnings import UnsupportedFieldAttributeWarning

                warnings.simplefilter(

       */
      try (URLClassLoader finalizerLoader = newLoader(getBaseUrl())) {
        return finalizerLoader.loadClass(FINALIZER_CLASS_NAME);
      } catch (Exception e) {
        logger.log(Level.WARNING, LOADING_ERROR, e);
        return null;
      }
    }

    /** Gets URL for base of path containing Finalizer.class. */
    URL getBaseUrl() throws IOException {

Nesta seção, você verá como gerenciar a autenticação e autorização com os mesmos escopos do OAuth2 em sua aplicação **FastAPI**.

/// warning | Atenção

Isso é uma seção mais ou menos avançada. Se você está apenas começando, você pode pular.

### Utilizando gerenciadores de contexto em dependências com `yield` { #using-context-managers-in-dependencies-with-yield }

/// warning | Atenção

Isso é uma ideia mais ou menos "avançada".

Se você está apenas iniciando com o **FastAPI** você pode querer pular isso por enquanto.

///

### Using context managers in dependencies with `yield` { #using-context-managers-in-dependencies-with-yield }

/// warning

This is, more or less, an "advanced" idea.

If you are just starting with **FastAPI** you might want to skip it for now.

///

   * null, null, null]} regardless of the true comparison order of those three values (which might
   * not even implement {@link Comparable} at all).
   *
   * <p><b>Warning:</b> by definition, this comparator is not <i>consistent with equals</i> (as
   * defined {@linkplain Comparator here}). Avoid its use in APIs, such as {@link
   * TreeSet#TreeSet(Comparator)}, where such consistency is expected.