}
    
    private class Producer implements Callable {
        public Object call() throws Exception {
            for (int i = 0; i < 5; i++) {
                ApplicationEvent produced = new PayloadEvent(this, new String("test-" + i), null);
                BlockingCollectorTest.this.collector.onApplicationEvent(produced);
                ApplicationEvent polled = BlockingCollectorTest.this.exchanger.exchange(produced);
                BlockingCollectorTest.this.assertSame(produced, polled);
            }
            return null;
        }