E quando a dependência for resolvida, o **FastAPI** chamará este `checker` como:

```Python
checker(q="somequery")
```

...e passar o que quer que isso retorne como valor da dependência em nossa *função de operação de rota* como o parâmetro `fixed_content_included`:

{* ../../docs_src/dependencies/tutorial011_an_py39.py hl[22] *}

/// tip | Dica

      Request
        .Builder()
        .url(server.url("/baz"))
        .query(RequestBody.EMPTY)
        .build()
    val response3 = client.newCall(request3).execute()
    assertThat(response3.body.string()).isEqualTo("DEF")
    val recordedRequest3 = server.takeRequest()
    assertThat(recordedRequest3.requestLine).isEqualTo("QUERY /baz HTTP/1.1")
    val request4 =
      Request
        .Builder()

     * This method queries the search engine for child documents and extracts their URLs.
     *
     * @param searchEngineClient the search engine client to query
     * @param id the parent document ID to find children for
     * @return a set of RequestData objects for the child URLs, or null if no children found
     */

	public final fun password ()Ljava/lang/String;
	public final fun pathSegments ()Ljava/util/List;
	public final fun pathSize ()I
	public final fun port ()I
	public final fun query ()Ljava/lang/String;
	public final fun queryParameter (Ljava/lang/String;)Ljava/lang/String;
	public final fun queryParameterName (I)Ljava/lang/String;
	public final fun queryParameterNames ()Ljava/util/Set;

* the contents of a file in the disk to be read by the system and given to your program
* 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.

* HTTP Basic.
* **OAuth2** (với **JWT tokens**). Xem hướng dẫn [OAuth2 with JWT](tutorial/security/oauth2-jwt.md){.internal-link target=_blank}.
* API keys in:
    * Headers.
    * Các tham số trong query string.
    * Cookies, etc.

Cộng với tất cả các tính năng bảo mật từ Starlette (bao gồm **session cookies**).

Durch die Verwendung von `Security` anstelle von `Depends` weiß **FastAPI** jedoch, dass es Sicherheits-Scopes deklarieren, intern verwenden und die API mit OpenAPI dokumentieren kann.

Wenn Sie jedoch `Query`, `Path`, `Depends`, `Security` und andere von `fastapi` importieren, handelt es sich tatsächlich um Funktionen, die spezielle Klassen zurückgeben.

///

## `SecurityScopes` verwenden

## `File` 매개변수 정의

`Body` 및 `Form` 과 동일한 방식으로 파일의 매개변수를 생성합니다:

{* ../../docs_src/request_files/tutorial001.py hl[7] *}

/// info | 정보

`File` 은 `Form` 으로부터 직접 상속된 클래스입니다.

하지만 `fastapi`로부터 `Query`, `Path`, `File` 등을 임포트 할 때, 이것들은 특별한 클래스들을 반환하는 함수라는 것을 기억하기 바랍니다.

///

/// tip | 팁

File의 본문을 선언할 때, 매개변수가 쿼리 매개변수 또는 본문(JSON) 매개변수로 해석되는  것을 방지하기 위해 `File` 을 사용해야합니다.

///

파일들은 "폼 데이터"의 형태로 업로드 됩니다.

* HTTP Basic.
* **OAuth2** (também com **tokens JWT**). Confira o tutorial em [OAuth2 com JWT](tutorial/security/oauth2-jwt.md){.internal-link target=_blank}.
* Chaves de API em:
    * Headers.
    * parâmetros da Query.
    * Cookies etc.

Além disso, todos os recursos de seguranças do Starlette (incluindo **cookies de sessão**).

}

func extractMetadata(ctx context.Context, mimesHeader ...textproto.MIMEHeader) (metadata map[string]string, err error) {
	metadata = make(map[string]string)

	for _, hdr := range mimesHeader {
		// Extract all query values.
		err = extractMetadataFromMime(ctx, hdr, metadata)
		if err != nil {
			return nil, err
		}
	}

	// Set content-type to default value if it is not set.