public void start() {
        gatewayThread = new GatewayRunner();
        feedbackThread = new FeedbackRunner();
        gatewayThread.start();
        feedbackThread.start();
        startUp.acquireUninterruptibly(2);
    }
Create an ApnsServerStub that uses any free port for gateway and feedback.

@return the server stub. Use getEffectiveGatewayPort() and getEffectiveFeedbackPort() to ask for ports.
src/test/java/com/notnoop/apns/utils/ApnsServerStub.java