Why System.Xml doesn't contain XmlDocument in Silverlight?

I cannot find this class in silverlight and searching the intern开发者_Go百科et has been clueless. So what's the equivalent of this class in silverlight ?

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XDocument -> Example

XDocument xmlStories = XDocument.Parse("</a>");
// or
XDocument xmlStories = XDocument.Load(stream);

Based on searches it appears Microsoft wanted a more LINQ friendly implementation which is XDocument.