* After adding a filter, the filter chain is recreated to include the new filter.
     *
     * @param filter the filter to add to the processing pipeline
     */
    public void addFilter(final Filter filter) {
        filterList.add(filter);
        createFilterChain();
    }

    /**
     * Creates the filter chain from the registered filters.

        assertTrue(called.get());
        assertEquals(BoolQueryBuilder.class, queryBuilder.getClass());

        called.set(false);
        final AtomicBoolean calledFirst = new AtomicBoolean(false);
        queryProcessor.addFilter(new QueryProcessor.Filter() {
            @Override
            public QueryBuilder execute(QueryContext context, Query query, float boost, FilterChain chain) {
                calledFirst.set(true);