You can import it directly from `fastapi`:

```python
from fastapi import BackgroundTasks
```

from fastapi import FastAPI
from pydantic import BaseModel


class Item(BaseModel):
    name: str
    description: str | None = None


app = FastAPI()


@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 typing import Any

import orjson
from fastapi import FastAPI, Response

app = FastAPI()


class CustomORJSONResponse(Response):
    media_type = "application/json"

    def render(self, content: Any) -> bytes:
        assert orjson is not None, "orjson must be installed"
        return orjson.dumps(content, option=orjson.OPT_INDENT_2)


@app.get("/", response_class=CustomORJSONResponse)
async def main():

from fastapi.testclient import TestClient

from docs_src.metadata.tutorial002_py39 import app

client = TestClient(app)


def test_items():
    response = client.get("/items/")
    assert response.status_code == 200, response.text
    assert response.json() == [{"name": "Foo"}]


def test_get_openapi_json_default_url():
    response = client.get("/openapi.json")
    assert response.status_code == 404, response.text

    private static final Logger logger = LogManager.getLogger(InputStreamThread.class);

    /** Buffered reader for reading from the input stream */
    private final BufferedReader br;

    /** Maximum buffer size constant */
    public static final int MAX_BUFFER_SIZE = 1000;

    /** List storing recent lines from the input stream */
    private final List<String> list = new LinkedList<>();

            return ComponentUtil.getComponent(name);
        }
        return null;
    }

    /**
     * Gets the configured SSO type from the system configuration.
     *
     * @return The SSO type string from configuration
     */
    protected String getSsoType() {
        return ComponentUtil.getFessConfig().getSsoType();
    }

    /**

     * @param parentImports The packages/types to import from the parent realm, may be {@code null}.
     * @param foreignImports The packages/types to import from foreign realms, may be {@code null}.
     * @param artifacts The artifacts to add to the class realm, may be {@code null}. Unresolved artifacts (i.e. with a
     *            missing file) will automatically be excluded from the realm.
     * @return The new plugin realm, never {@code null}.

from collections.abc import AsyncGenerator, Generator
from functools import partial
from typing import Annotated

import pytest
from fastapi import Depends, FastAPI
from fastapi.testclient import TestClient

app = FastAPI()


def function_dependency(value: str) -> str:
    return value


async def async_function_dependency(value: str) -> str:
    return value


def gen_dependency(value: str) -> Generator[str, None, None]:

from typing import Union

from fastapi import Depends, FastAPI
from fastapi.testclient import TestClient

app = FastAPI()


async def common_parameters(
    q: Union[str, None] = None, skip: int = 0, limit: int = 100
):
    return {"q": q, "skip": skip, "limit": limit}


@app.get("/items/")
async def read_items(commons: dict = Depends(common_parameters)):
    return {"message": "Hello Items!", "params": commons}

from fastapi import FastAPI
from fastapi.testclient import TestClient
from pydantic import BaseModel

app = FastAPI()


class UserBase(BaseModel):
    email: str


class UserCreate(UserBase):
    password: str


class UserDB(UserBase):
    hashed_password: str


class PetDB(BaseModel):
    name: str
    owner: UserDB


class PetOut(BaseModel):
    name: str
    owner: UserBase