def METHOD_NAME() -> Optional[Response]:
    """Store commonly used values in Flask's special g object"""
    i18n.set_locale(config)
    if InstanceConfig.get_default().organization_name:
        g.organization_name = (  # pylint: disable=assigning-non-slot
            InstanceConfig.get_default().organization_name
        )
    else:
        g.organization_name = gettext("SecureDrop")  # pylint: disable=assigning-non-slot
    try:
        g.logo = get_logo_url(app)  # pylint: disable=assigning-non-slot
    except FileNotFoundError:
        app.logger.error("Site logo not found.")
    if request.path.split("/")[1] == "api":
        if request.endpoint not in _insecure_api_views and not session.logged_in():
            abort(403)
    elif request.endpoint not in _insecure_views and not session.logged_in():
        return redirect(url_for("main.login"))
    if request.method == "POST":
        filesystem_id = request.form.get("filesystem_id")
        if filesystem_id:
            g.filesystem_id = filesystem_id  # pylint: disable=assigning-non-slot
            g.source = get_source(filesystem_id)  # pylint: disable=assigning-non-slot
    return None