Map<String, Object> doc3 = new HashMap<>();
        doc3.put("title", "Doc3");
        assertEquals(-1, qrList.indexOf(doc3));
    }

    public void test_listOperations_iterators() {
        List<Map<String, Object>> documentList = new ArrayList<>();
        Map<String, Object> doc1 = new HashMap<>();
        doc1.put("title", "Doc1");
        Map<String, Object> doc2 = new HashMap<>();