function Polling(opts) {
            var _this;

            _classCallCheck(this, Polling);

            _this = _super.call(this, opts);
            _this.polling = false;

            if (typeof location !== "undefined") {
                var isSSL = "https:" === location.protocol;
                var port = location.port; // some user agents have empty `location.port`

                if (!port) {
                    port = isSSL ? "443" : "80";
                }

                _this.xd = (typeof location !== "undefined" && opts.hostname !== location.hostname) || port !== opts.port;
                _this.xs = opts.secure !== isSSL;
            }
            /**
             * XHR supports binary
             */

            var forceBase64 = opts && opts.forceBase64;
            _this.supportsBinary = hasXHR2 && !forceBase64;
            return _this;
        }
XHR Polling constructor.

@param {Object} opts
@package