class TestEndpoint {

    @ReadOperation
    public User getUser(@Selector Integer id) {
        return new User(id, "james", 18);
    }

    @WriteOperation
    public User updateUser(int id, @Nullable String name, @Nullable Integer age) {<FILL_FUNCTION_BODY>}

}

        User user = getUser(id);
        user.setName(StringUtils.defaultIfBlank(name, user.getName()));
        user.setAge(ObjectUtils.defaultIfNull(age, user.getAge()));
        return user;
    
<no_super_class>