Stanza doesn't have a root. How can we keep the connection alive?

[cggaurav]

./node_modules/node-xmpp/lib/xmpp/session.js:129
    this.connection.send(stanza.root());
                                ^
TypeError: Object   has no method 'root'
    at Client.Session.send (./node_modules/node-xmpp/lib/xmpp/session.js:129:30)
    at Timer.<anonymous> (./node_modules/wobot/lib/bot.js:66:19)
    at Timer.exports.setInterval.timer.ontimeout (timers.js:234:14)