src.setTest("someTestValue");
ChildDOM child = newInstance(ChildDOM.class);
child.setChildName("someChildName");
src.setChild(child);
GenericDOM result = mapper.map(src, GenericDOM.class);
assertEquals("someTestValue", result.get("test"));
GenericDOM resultChild = (GenericDOM) result.get("child");
assertEquals("someChildName", resultChild.get("childName"));
}