I have been working on packaging a Site Definition using the Solutions Builder for VS 2008.  I have been able to create the solution and deploy it, but none of the features are activated.  So I found the SiteProvisioning.cs which allows the creation of code executed during site provisioning to activate features.  I have tried an number of different code snippets using SPweb.Feature.Add and SPsite.Feature.add can not get it to work correctly.  I can not find a fully functional example of this very simple step anywhere.  Does anyone have functioning example of activating any feature in the SiteProvisioning.cs file?