I use this for express app.js; ``` js app.use(session({ secret: 'keyboard cat', cookie: { maxAge: 60000 }})) ``` but, confirm me: ``` express-session deprecated undefined resave option; provide resave option app.js:49:9 express-session deprecated undefined saveUninitialized option; provide saveUninitialized option app.js:49:9 ``` and run confirm: ``` _http_outgoing.js:331 throw new Error('Can\'t set headers after they are sent.'); ``` why?