public void CreateAdShouldThrowIfCategoryIsNotSet()
        {
            // Arrange
            var carAdFactory = new CarAdFactory();

            // Act
            Action act = () => carAdFactory
                         .WithManufacturer("test")
                         .WithOptions(true, 4, TransmissionType.Manual)
                         .Build();

            // Assert
            act.Should().Throw <InvalidCarAdException>();
        }