public static void registerSubtype(Class<?> clz, String type) {
        mapper.registerSubtypes(new NamedType(clz, type));
    }
@Test
    void testRegisterSubtype() {
        JacksonUtils.registerSubtype(TestOfChild.class, "JacksonUtilsTest$TestOfChild");
        
        assertEquals(new TestOfChild(), JacksonUtils.toObj(
                "{\"@type\":\"JacksonUtilsTest$TestOfChild\",\"parentField\":\"parentValue\"," + "\"childField\":\"childValue\"}",
                TestOfParent.class));
    }