assertNotNull(result);
        assertEquals("innerValue", result.get("innerKey"));

        assertNull(MapValueExtractor.getMap(map, "missing"));
    }

    @Test
    public void testGetInteger() {
        Map<String, Object> map = new HashMap<>();
        map.put("int", 123);
        map.put("long", 456L);
        map.put("string", "789");