One of the limitations with using abstract classes is that there is no easy way to implement all of the overrides that are associated with an abstract class. Unlike an Interface whereby one can easily right click on the Interface name and select "Implement Interface", there is no such corresponding capability for abstract classes.
Therefore, implementing all of the necessary overrides can be very time consuming when working with the various ASP.Net Provider classes such as the XmlSiteMapProvider class.
This Item Template provides a shell of all of the necessary overrides for the XmlSiteMapProvider abstract class which developers can then use to fill out their own custom logic. It is available under the Visual C#/Web category for adding to Web Application projects.