In this section you will see how to manage authentication and authorization with the same OAuth2 with scopes in your **FastAPI** application.

/// warning

This is a more or less advanced section. If you are just starting, you can skip it.

You don't necessarily need OAuth2 scopes, and you can handle authentication and authorization however you want.

   * will be truncated to [byteCount] bytes.
   *
   * It is an error to call this method after the body has been consumed.
   *
   * **Warning:** this method loads the requested bytes into memory. Most applications should set
   * a modest limit on `byteCount`, such as 1 MiB.
   */
  @Throws(IOException::class)
  fun peekBody(byteCount: Long): ResponseBody {

    assertThrows(IllegalArgumentException.class, () -> Bytes.ensureCapacity(ARRAY1, 1, -1));
  }

  public void testToArray() {
    // need explicit type parameter to avoid javac warning!?
    List<Byte> none = Arrays.<Byte>asList();
    assertThat(Bytes.toArray(none)).isEqualTo(EMPTY);

    List<Byte> one = Arrays.asList((byte) 1);
    assertThat(Bytes.toArray(one)).isEqualTo(ARRAY1);

<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.

///

       */
      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 {

import org.jspecify.annotations.Nullable;

/**
 * A {@link SortedMultiset} whose contents will never change, with many other important properties
 * detailed at {@link ImmutableCollection}.
 *
 * <p><b>Warning:</b> as with any sorted collection, you are strongly advised not to use a {@link
 * Comparator} or {@link Comparable} type whose comparison behavior is <i>inconsistent with

   *
   * <p>Note however that if your escaper does not escape characters in the supplementary range, you
   * should either continue to validate the correctness of any surrogate characters encountered or
   * provide a clear warning to users that your escaper does not validate its input.
   *
   * <p>See {@link com.google.common.net.PercentEscaper} for an example.
   *
   * @param csq a sequence of characters

        Result<? extends ProjectDependencyGraph> graphResult = graphBuilder.build(session);
        for (ModelProblem problem : graphResult.getProblems()) {
            if (problem.getSeverity() == ModelProblem.Severity.WARNING) {
                logger.warn(problem.getMessage());
            } else {
                logger.error(problem.getMessage());
            }
        }

        if (!graphResult.hasErrors()) {

common:ios --noenable_platform_specific_config

# Suppress all C++ compiler warnings, otherwise build logs become 10s of MBs.
common:android --copt=-w
common:ios --copt=-w
common:linux --host_copt=-w
common:macos --copt=-w
common:windows --copt=/W0
common:windows --host_copt=/W0

# Suppress most C++ compiler warnings to reduce log size but allow
# for specific warnings to still be present.
common:linux --copt="-Wno-all"