class EventQueryParams extends DataQueryParams {

    public Set<Option> getItemOptions()
    {
        return getItemsAndItemFilters().stream()
            .filter( QueryItem::hasOptionSet )
            .map( q -> q.getOptionSet().getOptions() )
            .flatMap( q -> q.stream() )
            .collect( Collectors.toSet() );
    }

    private  EventQueryParams();

}