I'm trying to implement some of the magic of Examine Events from Shannon's CodeGarden presentation but there's one thing I can't work out. Per his example, when trying to add a node's XML to an examine index like this:

ExamineManager.Instance.ReIndexNode(umbXml.ToXDocument().Root, IndexTypes.Content);

...I'm told that ToXDocument isn't available, even though I have valid references to all the Examine and UmbracoExamine DLLs. I poked around and found that this seems to be part of the Umbraco.Examine LinqXmlExtensions, but I'm not sure what else I need to do to be able to use them. Any ideas? I'm sure it's something simple.

Thanks,
- Andrew