ReflectionTemplateBuilder builder = new ReflectionTemplateBuilder(registry);
Template<UserDefinedTypeFieldsClassNotNullable> tmpl = builder.buildTemplate(UserDefinedTypeFieldsClassNotNullable.class);
BufferPacker packer = msgpack.createBufferPacker();
tmpl.write(packer, v);
byte[] bytes = packer.toByteArray();
BufferUnpacker unpacker = msgpack.createBufferUnpacker();
unpacker.wrap(bytes);
UserDefinedTypeFieldsClassNotNullable ret = tmpl.read(unpacker, null);
assertEquals(v, ret);
}