code: public void addListener(SettingsEntityListener settingsEntityListener) {
      RunAsSystemAspect.runAsSystem(
          () ->
              entityListenersService.addEntityListener(
                  entityTypeId,
                  new EntityListener() {
                    @Override
                    public void postUpdate(Entity entity) {
                      settingsEntityListener.postUpdate(entity);
                    }
  
                    @Override
                    public Object getEntityId() {
                      return getEntityType().getId();
                    }
                  }));
    }
docs: Adds a listener for this settings entity that fires on entity updates
  
  @param settingsEntityListener listener for this settings entity