# `Response` class

You can declare a parameter in a *path operation function* or dependency to be of type `Response` and then you can set data for the response like headers or cookies.

You can also use it directly to create an instance of it and return it from your *path operations*.

You can import it directly from `fastapi`:

```python
from fastapi import Response
```

この例は冗長に見えるかもしれません。セキュリティとデータモデルユーティリティ関数および *path operations* が同じファイルに混在しているということを覚えておいてください。

しかし、ここに重要なポイントがあります。

セキュリティと依存性注入に関するものは、一度だけ書きます。

そして、それは好きなだけ複雑にすることができます。それでも、一箇所に、一度だけ書くのです。すべての柔軟性を備えます。

しかし、同じセキュリティシステムを使って何千ものエンドポイント（*path operations*）を持つことができます。

そして、それらエンドポイントのすべて（必要な、どの部分でも）がこうした依存関係や、あなたが作成する別の依存関係を再利用する利点を享受できるのです。

さらに、こうした何千もの *path operations* は、たった3行で表現できるのです:

Все способы [добавления `dependencies` (зависимостей) в *декораторах операций пути*](dependencies-in-path-operation-decorators.md){.internal-link target=_blank} по-прежнему применимы, но в данном случае зависимости применяются ко всем *операциям пути* приложения.

## Зависимости для групп *операций пути* { #dependencies-for-groups-of-path-operations }

	bucketReplProxiedDeleteTaggingRequestsFailures = "proxied_delete_tagging_requests_failures"
	bucketL                                        = "bucket"
	operationL                                     = "operation"
	targetArnL                                     = "targetArn"
)

var (
	bucketReplLastHrFailedBytesMD = NewGaugeMD(bucketReplLastHrFailedBytes,

## Dependências para conjuntos de *operações de rota* { #dependencies-for-groups-of-path-operations }

* the contents your program gave to the system to be written to disk
* a remote API operation
* a database operation to finish
* a database query to return the results
* etc.

As the execution time is consumed mostly by waiting for <abbr title="Input and Output">I/O</abbr> operations, they call them "I/O bound" operations.

     */
    Optional<Boolean> yes();

    /**
     * Returns the list of encryption goals to be executed.
     * These goals can include operations like "init", "add-server", "delete-server", etc.
     *
     * @return an {@link Optional} containing the list of goals, or empty if not specified
     */
    @Nonnull
    Optional<List<String>> goals();

	//   isTransaction: Indicates whether this operation is part of a transaction, which may affect the caching strategy.
	//   connPool: A connection pool that provides database connections.
	//   locker: A synchronization lock that is unlocked after initialization to avoid deadlocks.
	// Returns:
	//   *Stmt: A newly created statement object for executing SQL operations.
	//   error: An error if the statement preparation fails.

{* ../../docs_src/openapi_callbacks/tutorial001_py310.py hl[1,23] *}

### Create the callback *path operation* { #create-the-callback-path-operation }

To create the callback *path operation* use the same `APIRouter` you created above.

It should look just like a normal FastAPI *path operation*:

* It should probably have a declaration of the body it should receive, e.g. `body: InvoiceEvent`.

│   ├── main.py
│   └── test_main.py
```

Let's say that now the file `main.py` with your **FastAPI** app has some other **path operations**.

It has a `GET` operation that could return an error.

It has a `POST` operation that could return several errors.

Both *path operations* require an `X-Token` header.

{* ../../docs_src/app_testing/app_b_an_py310/main.py *}