assertEquals("value1", docMap.get("key1"));
        assertEquals("value2", docMap.get("key2"));
        assertEquals("value3", docMap.get("key3"));
    }

    @Test
    public void test_clear() {
        Map<String, Object> parentMap = new HashMap<>();
        DocMap docMap = new DocMap(parentMap);

        docMap.put("key1", "value1");
        docMap.put("key2", "value2");