assertEquals(doc2, qrList.get(0));

        assertTrue(qrList.remove(doc2));
        assertEquals(0, qrList.size());
        assertTrue(qrList.isEmpty());
    }

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