public void IsSubdomain_PassingInvalidArgumentsReturnErrors()
        {
            var mock = new FakeObject
            {
                Subdomain = FakeTypes.ReferenceTypes.ClassTypes.String_New(),
            };

            var validator = new FakeObjectValidator();

            validator.RuleFor(_ => _.Subdomain)
            .IsSubdomain()
            .IsSubdomain(nameof(FakeObject.Subdomain) + FakeObject.FIELD_NAME);

            // Validate
            var result   = validator.Validate(mock);
            var messages = result.ToString();

            Assert.IsFalse(result.IsValid);
            Assert.IsTrue(result.Errors.Count == 2);
            Assert.IsFalse(string.IsNullOrWhiteSpace(messages));
            Assert.IsTrue(messages.Contains(Messages.Subdomain(mock.Subdomain, nameof(FakeObject.Subdomain))));
            Assert.IsTrue(messages.Contains(Messages.Subdomain(mock.Subdomain, nameof(FakeObject.Subdomain) + FakeObject.FIELD_NAME)));
        }