[CommonMark syntax](https://commonmark.org/) MAY be used for rich
                    text representation.
                * `externalDocs`: Additional external documentation for this tag. If
                    provided, it would contain a `dict` with:
                    * `description`: A short description of the target documentation.

        app = FastAPI()
        internal_router = APIRouter()
        users_router = APIRouter()

        @users_router.get("/users/")
        def read_users():
            return [{"name": "Rick"}, {"name": "Morty"}]

        internal_router.include_router(users_router)
        app.include_router(internal_router)
        ```
        """
        if prefix: