FastAPIが実際にチェックしているのは、それが「呼び出し可能」（関数、クラス、その他なんでも）であり、パラメータが定義されているかどうかということです。

**FastAPI** の依存関係として「呼び出し可能なもの」を渡すと、その「呼び出し可能なもの」のパラメータを解析し、サブ依存関係も含めて、*path operation関数*のパラメータと同じように処理します。

それは、パラメータが全くない呼び出し可能なものにも適用されます。パラメータのない*path operation関数*と同じように。

そこで、上で紹介した依存関係の`common_parameters`を`CommonQueryParams`クラスに変更します:

```Python hl_lines="11 12 13 14 15"
{!../../docs_src/dependencies/tutorial002.py!}
```

			b := disk.AlignedBlock(SmallBlock)
			return &b
		},
	}
)

// WriteOnCloser implements io.WriteCloser and always
// executes at least one write operation if it is closed.
//
// This can be useful within the context of HTTP. At least
// one write operation must happen to send the HTTP headers
// to the peer.
type WriteOnCloser struct {
	io.Writer
	hasWritten bool
}

# Response Cookies

## Use a `Response` parameter

You can declare a parameter of type `Response` in your *path operation function*.

And then you can set cookies in that *temporal* response object.

```Python hl_lines="1  8-9"
{!../../docs_src/response_cookies/tutorial002.py!}
```

And then you can return any object you need, as you normally would (a `dict`, a database model, etc).

# Blocking vs Non-blocking

The default behavior of the ring buffer is non-blocking, 
meaning that reads and writes will return immediately with an error if the operation cannot be completed.
If you want to block when reading or writing, you must enable it:

```go
	rb := ringbuffer.New(1024).SetBlocking(true)
```

│   ├── __init__.py
│   ├── 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.

//// tab | Python 3.10+

```Python

    - tutorial/handling-errors.md
    - tutorial/path-operation-configuration.md
    - tutorial/encoder.md
    - tutorial/body-updates.md
    - Dependencies:
      - tutorial/dependencies/index.md
      - tutorial/dependencies/classes-as-dependencies.md
      - tutorial/dependencies/sub-dependencies.md
      - tutorial/dependencies/dependencies-in-path-operation-decorators.md
      - tutorial/dependencies/global-dependencies.md

And you can declare some of the files as `bytes` and some as `UploadFile`.

/// warning

You can declare multiple `File` and `Form` parameters in a *path operation*, but you can't also declare `Body` fields that you expect to receive as JSON, as the request will have the body encoded using `multipart/form-data` instead of `application/json`.

    """
    Create an invoice.

    This will (let's imagine) let the API user (some external developer) create an
    invoice.

    And this path operation will:

    * Send the invoice to the client.
    * Collect the money from the client.
    * Send a notification back to the API user (the external developer), as a callback.

    throw new UnsupportedOperationException();
  }

  @Override
  public ConcurrentMap<K, V> asMap() {
    throw new UnsupportedOperationException();
  }

  /**
   * Accumulates statistics during the operation of a {@link Cache} for presentation by {@link
   * Cache#stats}. This is solely intended for consumption by {@code Cache} implementors.
   *
   * @since 10.0
   */
  public interface StatsCounter {
    /**

   *     no change will be made.
   * @return the count of the element before the operation; possibly zero
   * @throws IllegalArgumentException if {@code occurrences} is negative, or if this operation would
   *     result in more than {@link Integer#MAX_VALUE} occurrences of the element