@Override
    public void subscribe(Class<? extends RootApplicationEvent> event, EventListener listener) {
        synchronized (subscriptions) {
            Set<EventListener> listeners = subscriptions.get(event);
            if (listeners == null) {
                listeners = new HashSet<>(1);
                listeners.add(listener);
            } else {
                listeners.add(listener);
                subscriptions.put(event, listeners);
            }
        }
    }
@ Override public void subscribe ( Class < ? extends RootApplicationEvent > event , EventListener listener ) { synchronized ( subscriptions ) { Set < EventListener > listeners = subscriptions . get ( event ) ; if ( listeners == null ) { listeners = new HashSet < > ( 1 ) ; listeners . add ( listener ) ; } else { listeners . add ( listener ) ; subscriptions . put ( event , listeners ) ; } } }
{@inheritDoc}