private <T extends Enum> void regsiterListener(
EventListener<T, ?> el, Class<T> enumClass, Collection<T> events) {
boolean found = false;
final Set<EventListenerDescriptor> descriptorSet = getOrCreateListenerSet(enumClass);
for (EventListenerDescriptor<T> descriptor : descriptorSet) {
if (descriptor.getListener() == el) {
descriptor.listenFor(events);
found = true;
break;
}
}
if (!found) {
descriptorSet.add(new EventListenerDescriptor<T>(el, events));
}
}
