code: private List<IGenericEvent<T>> getSubscribers(String eventName, boolean canCreate) {
          List<IGenericEvent<T>> subscribers = subscriptions.get(eventName);
          
          if (subscribers == null && canCreate) {
              subscribers = new LinkedList<>();
              subscriptions.put(eventName, subscribers);
          }
          
          return subscribers;
      }
docs: Gets the list of subscribers associated with an event.
  
  @param eventName Name of the event.
  @param canCreate If true and the list does not exist, create it.
  @return The requested list; may be null.