How to use the voila.paths.STATIC_ROOT function in voila

help=_(
            'path to nbconvert templates'
        )
    )

    template_paths = List(
        [],
        allow_none=True,
        config=True,
        help=_(
            'path to nbconvert templates'
        )
    )

    static_paths = List(
        [STATIC_ROOT],
        config=True,
        help=_(
            'paths to static assets'
        )
    )

    port_retries = Integer(50, config=True,
                           help=_("The number of additional ports to try if the specified port is not available.")
                           )

    ip = Unicode('localhost', config=True,
                 help=_("The IP address the notebook server will listen on."))

    open_browser = Bool(True, config=True,
                        help=_("""Whether to open in a browser after starting.
                        The specific browser used is platform dependent and

def load_jupyter_server_extension(server_app):
    web_app = server_app.web_app

    nbconvert_template_paths = []
    static_paths = [STATIC_ROOT]
    template_paths = []

    # common configuration options between the server extension and the application
    voila_configuration = VoilaConfiguration(parent=server_app)
    collect_template_paths(
        nbconvert_template_paths,
        static_paths,
        template_paths,
        voila_configuration.template
    )

    jenv_opt = {"autoescape": True}
    env = Environment(loader=FileSystemLoader(template_paths), extensions=['jinja2.ext.i18n'], **jenv_opt)
    web_app.settings['voila_jinja2_env'] = env

    nbui = gettext.translation('nbui', localedir=os.path.join(ROOT, 'i18n'), fallback=True)

8866,
        config=True,
        help=_(
            'Port of the voila server. Default 8866.'
        )
    )
    autoreload = Bool(
        False,
        config=True,
        help=_(
            'Will autoreload to server and the page when a template, js file or Python code changes'
        )
    )
    root_dir = Unicode(config=True, help=_('The directory to use for notebooks.'))
    static_root = Unicode(
        STATIC_ROOT,
        config=True,
        help=_(
            'Directory holding static assets (HTML, JS and CSS files).'
        )
    )
    aliases = {
        'port': 'Voila.port',
        'static': 'Voila.static_root',
        'strip_sources': 'VoilaConfiguration.strip_sources',
        'autoreload': 'Voila.autoreload',
        'template': 'VoilaConfiguration.template',
        'theme': 'VoilaConfiguration.theme',
        'base_url': 'Voila.base_url',
        'server_url': 'Voila.server_url',
        'enable_nbextensions': 'VoilaConfiguration.enable_nbextensions'
    }