public void Should_fail_validation_when_format_is_invalid()
        {
            const string EMAIL = "invalid_email_format";

            EMAIL.IsValidEmail().Should().BeFalse();
        }
        public void Should_pass_validation_with_good_email()
        {
            const string EMAIL = EmailData.EXISTING_CONTACT_EMAIL;

            EMAIL.IsValidEmail().Should().BeTrue();
        }