public void AddClassIfMissing_NoClasses_Adds()
{
var dom = new XmlDocument();
dom.LoadXml(@"<div class=''/>");
HtmlDom.AddClassIfMissing((XmlElement)dom.FirstChild, "two");
AssertThatXmlIn.Dom(dom).HasSpecifiedNumberOfMatchesForXpath("div[@class='two']", 1);
}