src/main/java/org/jivesoftware/whack/util/TaskEngine.java
public void shutdown() {
        if (executor != null) {
            executor.shutdownNow();
            executor = null;
        }

        if (timer != null) {
            timer.cancel();
            timer = null;
        }
    }
public void shutdown() {
        if (executor != null) {
            executor.shutdownNow();
            executor = null;
        }

        if (timer != null) {
            timer.cancel();
            timer = null;
        }
    }
Shuts down the task engine service.