可在一个*路径操作*中声明多个 `File` 和 `Form` 参数，但不能同时声明要接收 JSON 的 `Body` 字段。因为此时请求体的编码是 `multipart/form-data`，不是 `application/json`。

这不是 **FastAPI** 的问题，而是 HTTP 协议的规定。

///

## 可选文件上传

您可以通过使用标准类型注解并将 None 作为默认值的方式将一个文件参数设为可选:

//// tab | Python 3.9+

```Python hl_lines="7  14"
{!> ../../docs_src/request_files/tutorial001_02_py310.py!}
```

////

//// tab | Python 3.8+

// If an error is returned no goroutines have been started and r.err will have been set.
func (r *Reader) startReaders(newReader func(io.Reader) *csv.Reader) error {
	if r.args.FileHeaderInfo != none {
		// Read column names
		// Get one line.
		b, err := r.nextSplit(0, nil)
		if err != nil {
			r.err = err
			return err
		}
		if !utf8.Valid(b) {
			return errInvalidTextEncodingError()
		}

```

If the error type is `*RemoteErr`, then the error was returned by the remote server. Otherwise it is a local error.

Context timeouts are propagated, and a default timeout of 1 minute is added if none is specified.

There is no cancellation propagation for single payload requests.
When the context is canceled, the request will return at once with an appropriate error. 

	testGenerateOption(t, false, func(t *testing.T, actual, expected []admitv1.MutatingWebhook) {
		if err := assert.Compare(actual, expected); err == nil {
			t.Errorf("expected diff between webhooks, got none")
		}
	})

    val cookieBuilder =
      Cookie.Builder()
        .name("a")
        .value("b")
        .domain("example.com")
        .sameSite("None")

    val cookie = cookieBuilder.build()
    assertThat(cookie.sameSite).isEqualTo("None")
  }

  @Test fun equalsAndHashCode() {
    val cookieStrings =
      Arrays.asList(
        "a=b; Path=/c; Domain=example.com; Max-Age=5; Secure; HttpOnly",

 */
class HttpUrl private constructor(
  /** Either "http" or "https". */
  @get:JvmName("scheme") val scheme: String,
  /**
   * The decoded username, or an empty string if none is present.
   *
   * | URL                              | `username()` |
   * | :------------------------------- | :----------- |
   * | `http://host/`                   | `""`         |

			newKeys = append(newKeys, foundKey)
			newVals = append(newVals, foundVal)
		} else {
			found = true
		}
	}
	// If not found, just return.
	if !found {
		return false
	}
	// If none left...
	if len(newKeys) == 0 {
		*x = nil
		return true
	}

	// Reserialize...
	x.serialize(plSize, newKeys, newVals)
	return true
}

	if err := log.Configure(GetLoggingOptions(conf)); err != nil {
		log.Error("Failed to configure istio-cni logging")
	}

	var loggedPrevResult any
	if conf.PrevResult == nil {
		loggedPrevResult = "none"
	} else {
		loggedPrevResult = conf.PrevResult
	}
	log.WithLabels("if", args.IfName).Debugf("istio-cni CmdAdd config: %+v", conf)
	log.Debugf("istio-cni CmdAdd previous result: %+v", loggedPrevResult)

	}

	var update bool
	// Check if specified pools need to be removed from decommissioned pool.
	for k := range specifiedPools {
		pi, ok := rememberedPools[k]
		if !ok {
			// we do not have the pool anymore that we previously remembered, since all
			// the CLI checks out we can allow updates since we are mostly adding a pool here.
			update = true
		}
		if ok && pi.completed {

        }
        return artifactGeneratorFactories;
    }

    protected Map<String, ArtifactGeneratorFactory> createArtifactGeneratorFactories() {
        // by default none, this is extension point
        return new HashMap<>();
    }

    private Map<String, ArtifactDecoratorFactory> artifactDecoratorFactories;