Dúvida no Ex. 3 da Aula 6 - Manipulando cookies existentes

O meu codigo final ficou assim, mas funciona sem problemas:

@Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {
        HttpServletRequest req = (HttpServletRequest) request;
        HttpServletResponse resp = (HttpServletResponse) response;

        String usuario = getUsuario(req, resp);
        System.out.println("Usuário " + usuario + " acessando a URI " + req.getRequestURL());
        chain.doFilter(request, response);
    }

    private String getUsuario(HttpServletRequest req, HttpServletResponse resp) {
        Cookie cookie = new Cookies(req.getCookies()).buscaUsuarioLogado();
        if (cookie == null)
            return "<deslogado>";
        cookie.setMaxAge(10 * 60);
        resp.addCookie(cookie);
        return cookie.getValue();
    }

Sera que esta errado?