flat_models = callback_flat_models + list(
        body_fields_from_routes + responses_from_routes + request_fields_from_routes
    )
    return flat_models


def get_openapi(
    *,
    title: str,
    version: str,
    openapi_version: str = "3.1.0",
    summary: Optional[str] = None,
    description: Optional[str] = None,
    routes: Sequence[BaseRoute],