///

```Python hl_lines="22"
{!> ../../docs_src/dependencies/tutorial005.py!}
```

////

/// info

Notice that we are only declaring one dependency in the *path operation function*, the `query_or_cookie_extractor`.

But **FastAPI** will know that it has to solve `query_extractor` first, to pass the results of that to `query_or_cookie_extractor` while calling it.

///

```mermaid

                            Preamble

  The GNU Affero General Public License is a free, copyleft license for
software and other kinds of works, specifically designed to ensure
cooperation with the community in the case of network server software.

  The licenses for most software and other practical works are designed
to take away your freedom to share and change the works.  By contrast,

  override fun checkClientTrusted(
    chain: Array<out X509Certificate>,
    authType: String?,
  ) = throw CertificateException("Unsupported operation")

  override fun checkServerTrusted(
    chain: Array<out X509Certificate>,
    authType: String,
  ) = throw CertificateException("Unsupported operation")

import com.google.common.annotations.GwtCompatible;

/**
 * An object that can perform a {@link #tearDown} operation.
 *
 * @author Kevin Bourrillion
 * @since 10.0
 */
@FunctionalInterface
@GwtCompatible
@ElementTypesAreNonnullByDefault
public interface TearDown {
  /**
   * Performs a <b>single</b> tear-down operation. See test-libraries-for-java's {@code
   * com.google.common.testing.junit3.TearDownTestCase} and {@code

## Use the `Request` object directly

Let's imagine you want to get the client's IP address/host inside of your *path operation function*.

For that you need to access the request directly.

```Python hl_lines="1  7-8"
{!../../docs_src/using_request_directly/tutorial001.py!}
```

By declaring a *path operation function* parameter with the type being the `Request` **FastAPI** will know to pass the `Request` in that parameter.

/// tip

"Шлях" (path) також зазвичай називають "ендпоінтом" (endpoint) або "маршрутом" (route).

///

При створенні API, "шлях" є основним способом розділення "завдань" і "ресурсів".
#### Operation

"Операція" (operation) тут означає один з "методів" HTTP.

Один з:

* `POST`
* `GET`
* `PUT`
* `DELETE`

...та більш екзотичних:

* `OPTIONS`
* `HEAD`
* `PATCH`
* `TRACE`

  public void testRemove_nullKeyQueriesUnsupported() {
    try {
      assertFalse(getMap().remove(null, v3()));
    } catch (NullPointerException tolerated) {
      // since the operation would be a no-op, the exception is not required
    }
    expectUnchanged();
  }

  @MapFeature.Require(value = SUPPORTS_REMOVE, absent = ALLOWS_NULL_VALUE_QUERIES)

`response_model`は「デコレータ」メソッド（`get`、`post`など）のパラメータであることに注意してください。すべてのパラメータやボディのように、*path operation関数* のパラメータではありません。

///

Pydanticモデルの属性に対して宣言するのと同じ型を受け取るので、Pydanticモデルになることもできますが、例えば、`List[Item]`のようなPydanticモデルの`list`になることもできます。

FastAPIは`response_model`を使って以下のことをします:

* 出力データを型宣言に変換します。
* データを検証します。
* OpenAPIの *path operation* で、レスポンス用のJSON Schemaを追加します。
* 自動ドキュメントシステムで使用されます。

しかし、最も重要なのは:

import (
	"fmt"
	"os"
	"path"
)

// Wrapper functions to os.RemoveAll, which calls reliableRemoveAll
// this is to ensure that if there is a racy parent directory
// create in between we can simply retry the operation.
func removeAll(dirPath string) (err error) {
	if dirPath == "" {
		return errInvalidArgument
	}

	if err = checkPathLength(dirPath); err != nil {
		return err
	}

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

And now, we can use `__init__` to declare the parameters of the instance that we can use to "parameterize" the dependency: