O `TestClient` faz algumas mágicas para invocar a aplicação FastAPI assíncrona em suas funções `def` normais, utilizando o pytest padrão. Porém a mágica não acontece mais quando nós estamos utilizando dentro de funções assíncronas. Ao executar os nossos testes de forma assíncrona, nós não podemos mais utilizar o `TestClient` dentro das nossas funções de teste.

{* ../../docs_src/schema_extra_example/tutorial002_py310.py hl[2,8:11] *}

## JSON Schema에서의 `examples` - OpenAPI

이들 중에서 사용합니다:

* `Path()`
* `Query()`
* `Header()`
* `Cookie()`
* `Body()`
* `Form()`
* `File()`

**OpenAPI**의 **JSON 스키마**에 추가될 부가적인 정보를 포함한 `examples` 모음을 선언할 수 있습니다.

### `examples`를 포함한 `Body`

여기, `Body()`에 예상되는 예제 데이터 하나를 포함한 `examples`를 넘겼습니다:

   *
   * <p>The returned supplier is thread-safe. The delegate's {@code get()} method will be invoked at
   * most once unless the underlying {@code get()} throws an exception. The supplier's serialized
   * form does not contain the cached value, which will be recalculated when {@code get()} is called
   * on the deserialized instance.
   *
   * <p>When the underlying delegate throws an exception then this memoizing supplier will keep

                    "summary": "Login",
                    "operationId": "login_login__post",
                    "requestBody": {
                        "content": {
                            "application/x-www-form-urlencoded": {
                                "schema": {"$ref": "#/components/schemas/FormData"}
                            }
                        },
                        "required": True,
                    },

        def fetch_credentials():
            # HTTP headers are case insensitive filter out
            # all duplicate headers and pick one.
            headers = {}
            headers['content-type'] = 'application/x-www-form-urlencoded'
            headers['authorization'] = urllib3.make_headers(
                basic_auth='%s:%s' % (self.cid, self.csec))['authorization']

            response = self._http.urlopen('POST', self.idp_ep,

{* ../../docs_src/path_operation_advanced_configuration/tutorial003.py hl[6] *}

## docstringによる説明の高度な設定

*path operation関数* のdocstringからOpenAPIに使用する行を制限することができます。

`\f` (「書式送り (Form Feed)」のエスケープ文字) を付与することで、**FastAPI** はOpenAPIに使用される出力をその箇所までに制限します。

ドキュメントには表示されませんが、他のツール (例えばSphinx) では残りの部分を利用できるでしょう。

  For an executable, the required form of the "work that uses the
Library" must include any data and utility programs needed for
reproducing the executable from it.  However, as a special exception,
the materials to be distributed need not include anything that is
normally distributed (in either source or binary form) with the major
components (compiler, kernel, and so on) of the operating system on

				t.Errorf("Test %d: Expected the result to be \"%v\", but got \"%v\". ", i+1, testCase.expectedSignedHeaders, actualSignedHeaders)
			}
		}
	}
}

// TestParseSignV4 - Tests Parsing of v4 signature form the authorization string.
func TestParseSignV4(t *testing.T) {
	sampleTimeStr := UTCNow().Format(yyyymmdd)
	testCases := []struct {
		inputV4AuthStr    string
		expectedAuthField signValues

Aber `OAuth2PasswordRequestForm` ist nur eine Klassenabhängigkeit, die Sie selbst hätten schreiben können, oder Sie hätten `Form`ular-Parameter direkt deklarieren können.

Da es sich jedoch um einen häufigen Anwendungsfall handelt, wird er zur Vereinfachung direkt von **FastAPI** bereitgestellt.

///

### Die Formulardaten verwenden { #use-the-form-data }

/// tip | Tipp

    Object writeReplace() {
    return new SerializedForm<V>(map);
  }

  @GwtIncompatible
  @J2ktIncompatible
  /*
   * The mainline copy of ImmutableMapValues doesn't produce this serialized form anymore, though
   * the backport does. For now, we're keeping the class declaration in *both* flavors so that both
   * flavors can read old data or data from the other flavor. However, we strongly discourage