semaphore.releaseAsync().addListener(new FutureListener<Void>() { @Override public void operationComplete(Future<Void> future) throws Exception {
semaphore.releaseAsync().addListener(new FutureListener<Void>() { @Override public void operationComplete(Future<Void> future) throws Exception {
semaphore.releaseAsync().addListener(new FutureListener<Void>() { @Override public void operationComplete(Future<Void> future) throws Exception {