public void should_return_null_when_not_enabled()
        {
            // given
            var textSettings = new TextSettings()
            {
                UseHtmlWhiteList = false
            };
            HtmlSanitizerFactory factory = CreateFactory(textSettings);

            // when
            IHtmlSanitizer sanitizer = factory.CreateHtmlSanitizer();

            // then
            sanitizer.ShouldBeNull();
        }