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,

 * and localization purposes, as well as detailed error information. The message code
 * can be used by the UI layer to display appropriate error messages to users.
 */
public class SsoMessageException extends FessSystemException {

    private static final long serialVersionUID = 1L;

    /** The message code for internationalized error messages. */

/// 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!**

    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

* `/items/public/`
* `/items/private/`
* `/users/{user_id}/activate`
* `/items/pro/`

そして、依存関係とサブ依存関係だけで、それぞれに異なるパーミッション要件を追加することができます:

```mermaid
graph TB

current_user(["current_user"])
active_user(["active_user"])
admin_user(["admin_user"])
paying_user(["paying_user"])

public["/items/public/"]
private["/items/private/"]
activate_user["/users/{user_id}/activate"]
pro_items["/items/pro/"]