public ApnsServerSocketBuilder asPool(int maxConnections) {
		return asPool(new ThreadPoolExecutor(maxConnections, Integer.MAX_VALUE,
				60L, TimeUnit.SECONDS, new SynchronousQueue<Runnable>()));
	}
Constructs a pool of connections to the notification servers.

Apple servers recommend using a pooled connection up to 15 concurrent
persistent connections to the gateways.

Note: This option has no effect when using non-blocking connections.
src/test/java/com/notnoop/apns/ApnsServerSocketBuilder.java