nestedMap.put("outer", Maps.map("inner", "value").$());
        assertEquals(183L, MemoryUtil.sizeOf(nestedMap));
    }

    public void test_sizeOf_customObjects() {
        // Test fallback case for custom objects (should return 16L)
        assertEquals(16L, MemoryUtil.sizeOf(new Object()));
        assertEquals(16L, MemoryUtil.sizeOf(new CustomTestObject()));