public static void main(String[] args) {
    var user = new User("user", 24, Sex.FEMALE, "foobar.com");
    LOGGER.info(Validator.of(user).validate(User::name, Objects::nonNull, "name is null")
        .validate(User::name, name -> !name.isEmpty(), "name is empty")
        .validate(User::email, email -> !email.contains("@"), "email doesn't contains '@'")
        .validate(User::age, age -> age > 20 && age < 30, "age isn't between...").get()
        .toString());
  }
@Test
  void shouldExecuteApplicationWithoutException() {
    assertDoesNotThrow(() -> App.main(new String[]{}));
  }