その関数の中ですべての入力補完や型チェックを行う際に役に立ちます。

/// tip | 豆知識

リクエストボディはPydanticモデルでも宣言できることを覚えているかもしれません。

ここでは `Depends` を使っているおかげで、 **FastAPI** が混乱することはありません。

///

/// check | 確認

依存関係システムがこのように設計されているおかげで、 `User` モデルを返却する別の依存関係（別の「dependables」）を持つことができます。

同じデータ型を返却する依存関係は一つだけしか持てない、という制約が入ることはないのです。

///

## 別のモデル { #other-models }

/// tip

注意你傳給 `callback=` 的不是整個 router 本身（`invoices_callback_router`），而是它的屬性 `.routes`，也就是 `invoices_callback_router.routes`。

///

### 檢查文件 { #check-the-docs }

現在你可以啟動應用，並前往 [http://127.0.0.1:8000/docs](http://127.0.0.1:8000/docs)。

你會在文件中看到你的「路徑操作」包含一個「Callbacks」區塊，顯示「外部 API」應該長什麼樣子：

    } catch (InvocationTargetException e) {
      /*
       * It's theoretically possible for Reference.reachabilityFence to exist under older VMs but
       * not work. (Under Android in particular, we really should check the API Level instead of
       * probing for methods....) But it's hard to imagine how reachabilityFence in particular could
       * exist but throw, so we propagate anything that's thrown, presumably an unchecked Exception

To do that, we declare a method `__call__`:

{* ../../docs_src/dependencies/tutorial011_an_py310.py hl[12] *}

In this case, this `__call__` is what **FastAPI** will use to check for additional parameters and sub-dependencies, and this is what will be called to pass a value to the parameter in your *path operation function* later.

## Parameterize the instance { #parameterize-the-instance }

            return (Map<String, Object>) value;
        }
        return null;
    }

    /**
     * Checks if the map contains the specified key and the value is not null.
     *
     * @param map The source map
     * @param key The key to check
     * @return true if the key exists and its value is not null
     */

```console
$ fastapi run main.py --forwarded-allow-ips="*" --root-path /api/v1

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

### 檢查回應 { #check-the-responses }

現在，如果你前往 Uvicorn 的埠：[http://127.0.0.1:8000/app](http://127.0.0.1:8000/app)，你會看到一般的回應：

```JSON
{
    "message": "Hello World",
    "root_path": "/api/v1"
}
```

/// tip

     * @return true if the notification should be delivered
     */
    private boolean shouldDeliverNotification(WitnessRegistration registration, WitnessNotification notification) {
        // Check if notification is relevant to this registration
        String resourceName = notification.getResourceName();
        String shareName = registration.getShareName();

```console
$ fastapi run main.py --forwarded-allow-ips="*" --root-path /api/v1

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

### 查看响应 { #check-the-responses }

现在，如果你访问 Uvicorn 端口对应的 URL：[http://127.0.0.1:8000/app](http://127.0.0.1:8000/app)，你会看到正常响应：

```JSON
{
    "message": "Hello World",
    "root_path": "/api/v1"
}
```

        assertEquals(75L, merged.getDocFreq()); // Sum of frequencies
        assertEquals(1.5f, merged.getUserBoost(), 0.001f); // Takes item2's boost

        // Check merged arrays contain both items' values
        assertTrue(merged.getTags().length >= 2);
        assertTrue(merged.getRoles().length >= 2);
        assertTrue(merged.getLanguages().length >= 2);

	}
	if final == nil {
		return cache, errors.New("no final cache")
	}
	return *final, nil
}

func (client *storageRESTClient) GetDiskID() (string, error) {
	if !client.IsOnlineWS() {
		// make sure to check if the disk is offline, since the underlying
		// value is cached we should attempt to invalidate it if such calls
		// were attempted. This can lead to false success under certain conditions