"paths": {
            "/items/{item_id}": {
                "get": {
                    "responses": {
                        "404": {
                            "description": "The item was not found",
                            "content": {
                                "application/json": {
                                    "schema": {"$ref": "#/components/schemas/Message"}

                "get": {
                    "responses": {
                        "200": {
                            "description": "Successful Response",
                            "content": {"application/json": {"schema": {}}},
                        },
                        "422": {
                            "description": "Validation Error",
                            "content": {
                                "application/json": {

import org.lastaflute.web.response.StreamResponse;
import org.lastaflute.web.util.LaServletContextUtil;

import jakarta.annotation.PostConstruct;

/**
 * Helper class for Open Search Description Document.
 */
public class OsddHelper {

    /**
     * Default constructor.
     */
    public OsddHelper() {
        // Default constructor
    }

	<groupId>org.codelibs</groupId>
	<artifactId>corelib</artifactId>
	<packaging>jar</packaging>
	<name>CodeLibs Core Library</name>
	<version>0.7.2-SNAPSHOT</version>
	<description>Core library providing essential utilities and functionalities.</description>
	<url>https://github.com/codelibs/corelib</url>
	<inceptionYear>2012</inceptionYear>
	<licenses>
		<license>
			<name>The Apache Software License, Version 2.0</name>

class Item(BaseModel):
    name: str
    description: Optional[str] = None


app = FastAPI(separate_input_output_schemas=False)


@app.post("/items/")
def create_item(item: Item):
    return item


@app.get("/items/")
def read_items() -> list[Item]:
    return [
        Item(
            name="Portal Gun",
            description="Device to travel through the multi-rick-verse",
        ),

from fastapi import FastAPI
from pydantic import BaseModel as BaseModelV2
from pydantic.v1 import BaseModel


class Item(BaseModel):
    name: str
    description: Union[str, None] = None
    size: float


class ItemV2(BaseModelV2):
    name: str
    description: Union[str, None] = None
    size: float


app = FastAPI()


@app.post("/items/", response_model=ItemV2)
async def create_item(item: Item):

```Python hl_lines="3  5"
{
    "name": "Bar",
    "description": "The bartenders",
    "price": 62,
    "tax": 20.2
}
```
вони будуть включені у відповідь.

#### Дані з тими самими значеннями, що й типові

Якщо дані мають ті самі значення, що й типові, як у елемента з item_id `baz`:

```Python hl_lines="3  5-6"
{
    "name": "Baz",
    "description": None,
    "price": 50.2,
    "tax": 10.5,

```Python hl_lines="3  5-6"
{
    "name": "Baz",
    "description": None,
    "price": 50.2,
    "tax": 10.5,
    "tags": []
}
```

FastAPI достаточно умен (на самом деле, это Pydantic), чтобы понять, что хотя `description`, `tax` и `tags` совпадают со значениями по умолчанию, они были установлены явно (а не взяты из значений по умолчанию).

        this.departmentNumber = value;
    }

    public String getDescription() {
        checkSpecifiedProperty("description");
        return convertEmptyToNull(description);
    }

    public void setDescription(String value) {
        registerModifiedProperty("description");
        this.description = value;
    }

    public String getDestinationIndicator() {
        checkSpecifiedProperty("destinationIndicator");

    price: float
    tags: list[str] = field(default_factory=list)
    description: Union[str, None] = None
    tax: Union[float, None] = None


app = FastAPI()


@app.get("/items/next", response_model=Item)
async def read_next_item():
    return {
        "name": "Island In The Moon",
        "price": 12.99,
        "description": "A place to be playin' and havin' fun",
        "tags": ["breater"],