assertNotNull(results);
        }
    }

    /**
     * Test that all searchers failing still returns empty result gracefully.
     */
    @Test
    public void test_allSearchersFail() throws Exception {
        try (RankFusionProcessor processor = new RankFusionProcessor()) {
            processor.setSearcher(new ExceptionThrowingSearcher(new RuntimeException("Main searcher failed")));