private void AssertValidationResult <T>(Expression <Func <ChangeVersionViewModel, T> > property, ChangeVersionViewModel instance, bool expectedValid)
        {
            var validator = new ChangeVersionViewModelValidator();

            if (expectedValid)
            {
                validator.ShouldNotHaveValidationErrorFor(property, instance);
            }
            else
            {
                validator.ShouldHaveValidationErrorFor(property, instance);
            }
        }