We see that we are going to need some dependencies used in several places of the application.

So we put them in their own `dependencies` module (`app/dependencies.py`).

We will now use a simple dependency to read a custom `X-Token` header:

//// tab | Python 3.9+

```Python hl_lines="3  6-8" title="app/dependencies.py"
{!> ../../docs_src/bigger_applications/app_an_py39/dependencies.py!}
```

////

//// tab | Python 3.8+

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

➡️ 💬 👈 🔜 📁 `main.py` ⏮️ 👆 **FastAPI** 📱 ✔️ 🎏 **➡ 🛠️**.

⚫️ ✔️ `GET` 🛠️ 👈 💪 📨 ❌.

⚫️ ✔️ `POST` 🛠️ 👈 💪 📨 📚 ❌.

👯‍♂️ *➡ 🛠️* 🚚 `X-Token` 🎚.

//// tab | 🐍 3️⃣.6️⃣ & 🔛

```Python
{!> ../../docs_src/app_testing/app_b/main.py!}
```

////

//// tab | 🐍 3️⃣.1️⃣0️⃣ & 🔛

```Python

	}

	if subtle.ConstantTimeCompare([]byte(resp.Header.Get(xhttp.AmzRequestToken)), []byte(eventData.GetObjectContext.OutputToken)) != 1 {
		tokenErr := errorCodes.ToAPIErr(ErrInvalidToken)
		tokenErr.Description = "The request token included in the request is invalid"
		writeErrorResponse(ctx, w, tokenErr, r.URL)
		return
	}

	// Set all the relevant lambda forward headers if found.
	fwdHeadersToS3(resp.Header, w)

 *
 * <p>There are three Win32 function calls provided by the Windows SDK
 * that are important in the context of using jCIFS. They are:
 *
 * <ul>
 * <li> <code>CallNamedPipe</code> A message-type pipe call that opens,
 *      writes to, reads from, and closes the pipe in a single operation.
 * <li> <code>TransactNamedPipe</code> A message-type pipe call that
 *      writes to and reads from an existing pipe descriptor in one operation.

 *
 * <p>
 * There are three Win32 function calls provided by the Windows SDK
 * that are important in the context of using jCIFS. They are:
 *
 * <ul>
 * <li><code>CallNamedPipe</code> A message-type pipe call that opens,
 * writes to, reads from, and closes the pipe in a single operation.
 * <li><code>TransactNamedPipe</code> A message-type pipe call that
 * writes to and reads from an existing pipe descriptor in one operation.

*경로 작동 데코레이터*에서 `dependencies`를 사용하면 편집기/도구 오류를 피하며 실행되도록 할 수 있습니다.

또한 코드에서 사용되지 않는 매개변수를 보고 불필요하다고 생각할 수 있는 새로운 개발자의 혼란을 방지하는데 도움이 될 수 있습니다.

///

/// info | "정보"

이 예시에서 `X-Key`와 `X-Token`이라는 커스텀 헤더를 만들어 사용했습니다.

그러나 실제로 보안을 구현할 때는 통합된 [보안 유틸리티 (다음 챕터)](../security/index.md){.internal-link target=_blank}를 사용하는 것이 더 많은 이점을 얻을 수 있습니다.

///

## 의존성 오류와 값 반환하기

평소에 사용하던대로 같은 의존성 *함수*를 사용할 수 있습니다.

            if ( initialToken != null && initialToken.length > 0 ) {
                NegTokenInit tok = new NegTokenInit(initialToken);
                if ( log.isDebugEnabled() ) {
                    log.debug("Have initial token " + tok);
                }
                if ( tok.getMechanisms() != null ) {
                    Set<ASN1ObjectIdentifier> mechs = new HashSet<>(Arrays.asList(tok.getMechanisms()));

          public void run() {
            task.interruptTask();
          }
        };
    interrupter.start();
    // this will happen once the interrupt has been set which means that
    // 1. the runner has been woken up
    // 2. the interrupter is stuck in the call the Thread.interrupt()

    // after some period of time the runner thread should become blocked on the task because it is

labels.roleTypeIds=Rollen-ID
labels.scriptData=Skript
labels.scriptResult=Suchergebnis
labels.scriptType=Executor
labels.segmentation=Segmentierung
labels.startTime=Startzeitpunkt
labels.target=Ziel
labels.token=Token
labels.synonymFile=Datei mit Synonymen
labels.elevateWordFile=Datei mit zusätzlichen Wörtern
labels.badWordFile=Datei mit verbotenen Wörtern
labels.mappingFile=Datei mit Zuordnung
labels.boostExpr=Boost-Ausdruck

Ele tem uma operação `GET` que pode retornar um erro.

Ele tem uma operação `POST` que pode retornar vários erros.

Ambas as *operações de rotas* requerem um cabeçalho `X-Token`.

//// tab | Python 3.10+

```Python
{!> ../../docs_src/app_testing/app_b_an_py310/main.py!}
```

////

//// tab | Python 3.9+

```Python