code: @SuppressWarnings("SynchronizationOnLocalVariableOrMethodParameter")
      public void unregisterEventListener(EventModel<EventModel> event, EventListenerModel eventListener) throws IllegalArgumentException {
          for (String id : event.getAllInformations()) {
              ArrayList<EventListenerModel> listenersList = listeners.get(id);
              if (listenersList == null) {
                  return;
              }
              synchronized (listenersList) {
                  listenersList.remove(eventListener);
              }
          }
      }
docs: unregister an EventListener
  
  It will unregister for all Descriptors individually!
  It will also ignore if this listener is not listening to an Event.
  Method is thread-safe.
  
  @param event the Event to stop listen to
  @param eventListener the ActivatorEventListener used to listen for events
  @throws IllegalArgumentException if Listener is already listening to the Event or the id is not allowed