public void start(int numThreads) {
for (int i = 0; i < numThreads; i++) {
final IOLoop ioLoop = new IOLoop();
ioLoops.add(ioLoop);
final HttpProtocol protocol = new HttpProtocol(ioLoop, application);
new Thread(new Runnable() {
@Override public void run() {
registerHandler(ioLoop, protocol);
ioLoop.start();