protected void deinitInThread() {
        listener.destroy();
        timer = null;
        synchronized (createdLock) {
            created.set(false);
            createdLock.notifyAll();
        }
    }
Accesses the listener that receives events related to this context.

@return the pre-existing instance
jme3-core/src/main/java/com/jme3/system/NullContext.java