private final Multimap<Class<? extends Notification>, NotificationListenerRegistration<?>> listeners =
Multimaps.synchronizedSetMultimap(HashMultimap.<Class<? extends Notification>, NotificationListenerRegistration<?>>create());
private final Multimap<Class<? extends Notification>, NotificationListenerRegistration<?>> listeners =
Multimaps.synchronizedSetMultimap(HashMultimap.<Class<? extends Notification>, NotificationListenerRegistration<?>>create());