single_not_embedded_field = True
        # If headers are in a Pydantic model, the way to disable convert_underscores
        # would be with Header(convert_underscores=False) at the Pydantic model level
        default_convert_underscores = getattr(
            first_field.field_info, "convert_underscores", True
        )

    params_to_process: dict[str, Any] = {}

    processed_keys = set()

    Result (German):

        «««
        //// tab | Linux, macOS, Windows Bash
        Hallo wieder
        ////
        »»»


### Headings

Every Markdown heading in the English text (all levels) ends with a part inside curly brackets. This part denotes the hash of this heading, which is used in links to this heading. In translations, translate the heading, but do not translate this hash part, so that links do not break.

    * Original PR [#722](https://github.com/tiangolo/fastapi/pull/722) by [@booooh](https://github.com/booooh).
* Refactor logging to use the same logger everywhere, update log strings and levels. PR [#781](https://github.com/tiangolo/fastapi/pull/781).

                [FastAPI docs for `lifespan`](https://fastapi.tiangolo.com/advanced/events/).
                """
            ),
        ] = None,
        # the generic to Lifespan[AppType] is the type of the top level application
        # which the router cannot know statically, so we use typing.Any
        lifespan: Annotated[
            Optional[Lifespan[Any]],
            Doc(
                """