public void WhenNameIsNotProvided_ThenThrowException()
        {
            var user = new User {
                Email = "*****@*****.**"
            };

            try
            {
                userValidator.Validate(user);
            }
            catch (Exception ex)
            {
                var fieldIsRequiredMessage = ValidationMessages.GetFieldIsRequiredMessage(nameof(User.Name));
                Assert.AreEqual(fieldIsRequiredMessage, ex.Message);
                return;
            }

            Assert.Fail("Should throw exception when email is not provided.");
        }