6 var XHR = require('./polling-xhr');
7 var JSONP = require('./polling-jsonp');
13 module.exports = exports = {
15 websocket: require('./websocket')
19 * Export upgrades map.
22 exports.polling.upgradesTo = ['websocket'];
25 * Polling polymorphic constructor.
30 function polling (req) {
31 if ('string' === typeof req._query.j) {
32 return new JSONP(req);