@Override
    public Optional<String> validate(String password) {
        final String LENGTH_REASONING = "must be length of between " + minimumLength + " and " + MAXIMUM_LENGTH;
        return Strings.isNullOrEmpty(password) || password.length() < minimumLength
                ? Optional.of(LENGTH_REASONING)
                : Optional.empty();
    }
@Test
    public void testValidateSuccess() {
        Optional<String> result = lengthValidator.validate("Password123");
        Assert.assertFalse(result.isPresent());
    }