price: float

    Item = Annotated[
        Union[Annotated[FirstItem, Tag("first")], Annotated[OtherItem, Tag("other")]],
        Field(discriminator="value"),
    ]

    @app.post("/items/")
    def save_union_body_discriminator(
        item: Item, q: Annotated[str, Field(description="Query string")]
    ) -> dict[str, Any]:
        return {"item": item}

    client = TestClient(app)

        // Then - verify fields are set correctly using reflection
        Field commandField = ServerMessageBlock2.class.getDeclaredField("command");
        commandField.setAccessible(true);
        int command = (int) commandField.get(req);
        assertEquals(0x0001, command); // SMB2_SESSION_SETUP command value

        Field securityModeField = Smb2SessionSetupRequest.class.getDeclaredField("securityMode");

	public static final field INSTANCE Lokhttp3/brotli/Brotli;
	public fun decompress (Lokio/BufferedSource;)Lokio/Source;
	public fun getEncoding ()Ljava/lang/String;
}

public final class okhttp3/brotli/BrotliInterceptor : okhttp3/CompressionInterceptor {
	public static final field INSTANCE Lokhttp3/brotli/BrotliInterceptor;

            {
                "type": "missing",
                "loc": ["body", "grant_type"],
                "msg": "Field required",
                "input": None,
            },
            {
                "type": "missing",
                "loc": ["body", "username"],
                "msg": "Field required",
                "input": None,
            },
            {
                "type": "missing",

            {
                "type": "missing",
                "loc": ["body", "grant_type"],
                "msg": "Field required",
                "input": None,
            },
            {
                "type": "missing",
                "loc": ["body", "username"],
                "msg": "Field required",
                "input": None,
            },
            {
                "type": "missing",

	b.set = true
	return nil
}

// MarshalXML encodes expiration field into an XML form.
func (e Expiration) MarshalXML(enc *xml.Encoder, startElement xml.StartElement) error {
	if !e.set {
		return nil
	}
	type expirationWrapper Expiration
	return enc.EncodeElement(expirationWrapper(e), startElement)
}

// UnmarshalXML decodes expiration field from the XML form.

这些额外的信息将按原样添加到输出的JSON模式中。

## `Field` 的附加参数

在 `Field`, `Path`, `Query`, `Body` 和其他你之后将会看到的工厂函数，你可以为JSON 模式声明额外信息，你也可以通过给工厂函数传递其他的任意参数来给JSON 模式声明额外信息，比如增加 `example`:

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

/// warning

请记住，传递的那些额外参数不会添加任何验证，只会添加注释，用于文档的目的。

///

## `Body` 额外参数

你可以通过传递额外信息给 `Field` 同样的方式操作`Path`, `Query`, `Body`等。

        // Arrange
        SecurityBlob blob = new SecurityBlob(new byte[] { 1, 2, 3 });

        // Force internal field to null via reflection to exercise defensive branch
        Field field = SecurityBlob.class.getDeclaredField("b");
        field.setAccessible(true);
        field.set(blob, null);

        // Act & Assert
        assertEquals(0, blob.length(), "length() should return 0 when internal array is null");

                    )
                    field = route.response_fields.get(additional_status_code)
                    additional_field_schema: Optional[dict[str, Any]] = None
                    if field:
                        additional_field_schema = get_schema_from_model_field(
                            field=field,
                            model_name_map=model_name_map,

public interface SMBSigningDigest {

    /**
     * Performs MAC signing of the SMB. This is done as follows.
     * The signature field of the SMB is overwritten with the sequence number;
     * The MD5 digest of the MAC signing key + the entire SMB is taken;
     * The first 8 bytes of this are placed in the signature field.
     *
     * @param data
     *            The data.
     * @param offset