"4XX",
        "5XX",
    }:
        return True
    current_status_code = int(status_code)
    return not (current_status_code < 200 or current_status_code in {204, 205, 304})


def get_path_param_names(path: str) -> Set[str]:
    return set(re.findall("{(.*?)}", path))


def create_model_field(
    name: str,
    type_: Any,
    class_validators: Optional[Dict[str, Validator]] = None,

from fastapi.security.base import SecurityBase
from fastapi.security.oauth2 import OAuth2, SecurityScopes
from fastapi.security.open_id_connect_url import OpenIdConnect
from fastapi.utils import create_model_field, get_path_param_names
from pydantic import BaseModel
from pydantic.fields import FieldInfo
from starlette.background import BackgroundTasks as StarletteBackgroundTasks
from starlette.concurrency import run_in_threadpool

* Fix generating OpenAPI for apps using callbacks with routers including Pydantic models. PR [#1322](https://github.com/tiangolo/fastapi/pull/1322) by [@nsidnev](https://github.com/nsidnev).
* Optimize internal regex performance in `get_path_param_names()`. PR [#1243](https://github.com/tiangolo/fastapi/pull/1243) by [@heckad](https://github.com/heckad).