code: private void unsubscribeByEventType(Object subscriber, Class<?> eventType) {
          List<Subscription> subscriptions = subscriptionsByEventType.get(eventType);
          if (subscriptions != null) {
              int size = subscriptions.size();
              for (int i = 0; i < size; i++) {
                  Subscription subscription = subscriptions.get(i);
                  if (subscription.subscriber == subscriber) {
                      subscription.active = false;
                      subscriptions.remove(i);
                      i--;
                      size--;
                  }
              }
          }
      }
docs: Only updates subscriptionsByEventType, not typesBySubscriber! Caller must update typesBySubscriber.