Add directory to serve static files.

    First argument ``prefix`` is a URL prefix for the ``path``. ``path`` must
    be a directory. If ``no_watch`` is True, any change of the files in the
    path do not trigger restart if ``--autoreload`` is enabled.

def add_static_path(prefix: str, path: str, no_watch: bool = False) -> None:
    """Add directory to serve static files.

    First argument ``prefix`` is a URL prefix for the ``path``. ``path`` must
    be a directory. If ``no_watch`` is True, any change of the files in the
    path do not trigger restart if ``--autoreload`` is enabled.
    """
    app = get_app()
    app.add_static_path(prefix, path)
    if not no_watch:
        watch_dir(path)