te":{"Version":"2012-10-17","Statement":[{"Effect":"Allow","Action":["s3:*"],"Resource":["arn:aws:s3:::*"]}]},writeonly":{"Version":"2012-10-17","Statement":[{"Effect":"Allow","Action":["s3:PutObject"],"Resource":["arn:aws:s3:::*"]}]}} iam-assets/users.json {} iam-assets/groups.json {} iam-assets/svcaccts.json {"dillon-service-2":{"parent":"oCnAoSQFtdVQtKwrB73j","accessKey":"dillon-service-2","secretKey":"dillon-service-2","groups":null,"claims":{"accessKey":"dillon-service-2","at_hash":"LL4jvrk...

  PATH_SEPARATOR("path.separator"),

  /** Line separator ("\n" on UNIX). */
  LINE_SEPARATOR("line.separator"),

  /** User's account name. */
  USER_NAME("user.name"),

  /** User's home directory. */
  USER_HOME("user.home"),

  /** User's current working directory. */
  USER_DIR("user.dir");

  private final String key;

  StandardSystemProperty(String key) {
    this.key = key;
  }

    Property<String> getSomeProperty()
}
class Example {
    Property<NestedType> getNestedProperty()
}
```

This is unnecessary because users will have trouble creating instances of `NestedType` and merging different instances of `NestedType`. It's also more awkward for users to access the properties in the nested property.

If the nested type is a managed type (Gradle can generate its implementation), you can define a nested property with:

     */
    InputStream getInputStream() throws IOException;

    /**
     * Provides a user-friendly hint about the location of the source. This could be a local file path, a URI or just an
     * empty string. The intention is to assist users during error reporting.
     *
     * @return A user-friendly hint about the location of the source, never {@code null}.
     */
    String getLocation();

   *
   * <p>To collect to an {@link ImmutableTable}, use {@link ImmutableTable#toImmutableTable}.
   *
   * @since 33.2.0 (available since 21.0 in guava-jre)
   */
  @IgnoreJRERequirement // Users will use this only if they're already using streams.
  public static <
          T extends @Nullable Object,
          R extends @Nullable Object,
          C extends @Nullable Object,
          V,

/// tip

您可以在 `description` 字段中编写 Markdown，它将在输出中呈现。

///

通过这样设置，自动 API 文档看起来会像：

<img src="/img/tutorial/metadata/image01.png">

## 标签元数据

### 创建标签元数据

让我们在带有标签的示例中为 `users` 和 `items` 试一下。

创建标签元数据并把它传递给 `openapi_tags` 参数：

{* ../../docs_src/metadata/tutorial004.py hl[3:16,18] *}

注意你可以在描述内使用 Markdown，例如「login」会显示为粗体（**login**）以及「fancy」会显示为斜体（_fancy_）。

/// tip | 提示

   *
   * @throws IOException if an I/O error occurs while writing to this sink
   * @since 33.4.0 (but since 22.0 in the JRE flavor)
   */
  @IgnoreJRERequirement // Users will use this only if they're already using Stream.
  public void writeLines(Stream<? extends CharSequence> lines) throws IOException {
    writeLines(lines, LINE_SEPARATOR.value());
  }

  /**

1. APIs marked with the `@Beta` annotation at the class or method level
are subject to change. They can be modified in any way, or even
removed, at any time. If your code is a library itself (i.e. it is
used on the CLASSPATH of users outside your own control), you should
not use beta APIs, unless you [repackage] them. **If your
code is a library, we strongly recommend using the [Guava Beta Checker] to
ensure that you do not use any `@Beta` APIs!**

    user = UserInDB(**user_dict)
    hashed_password = fake_hash_password(form_data.password)
    if not hashed_password == user.hashed_password:
        raise HTTPException(status_code=400, detail="Incorrect username or password")

    return {"access_token": user.username, "token_type": "bearer"}


@app.get("/users/me")
async def read_users_me(current_user: User = Depends(get_current_active_user)):

import com.google.common.annotations.GwtCompatible;

/**
 * A time source; returns a time value representing the number of nanoseconds elapsed since some
 * fixed but arbitrary point in time. Note that most users should use {@link Stopwatch} instead of
 * interacting with this class directly.
 *
 * <p><b>Warning:</b> this interface can only be used to measure elapsed time, not wall time.
 *
 * @author Kevin Bourrillion