open() {
        let transport;
        if (this.opts.rememberUpgrade &&
            Socket.priorWebsocketSuccess &&
            this.transports.indexOf("websocket") !== -1) {
            transport = "websocket";
        }
        else if (0 === this.transports.length) {
            // Emit error on next tick so it can be listened to
            this.setTimeoutFn(() => {
                this.emitReserved("error", "No transports available");
            }, 0);
            return;
        }
        else {
            transport = this.transports[0];
        }
        this.readyState = "opening";
        // Retry with the next transport if the transport is disabled (jsonp: false)
        try {
            transport = this.createTransport(transport);
        }
        catch (e) {
            this.transports.shift();
            this.open();
            return;
        }
        transport.open();
        this.setTransport(transport);
    }
Initializes transport to use and starts probe.

@api private