anchor.diff:          let node = this.CreateNode(name)
           node.InnerText <- text
           node
  -
  -    member this.DeleteEmptyReferences() = 
  -        this.DeleteIfEmpty("//ns:ItemGroup")
  -        this.DeleteIfEmpty("//ns:When")
  -        this.DeleteIfEmpty("//ns:Otherwise")
  -        this.DeleteIfEmpty("//ns:Choose")
  -        this.DeleteIfEmpty("//ns:When")
  -        this.DeleteIfEmpty("//ns:Choose")
   
       member this.createFileItemNode fileItem =
           this.CreateNode(fileItem.BuildAction)
  
positive.code: 
      member this.UpdateReferences(completeModel: Map<string,InstallModel>, usedPackages : Dictionary<string,bool>, hard) = 
          this.DeletePaketNodes("Reference")  
          this.DeleteEmptyReferences()
  
          if hard then
              for kv in usedPackages do
  
negative.code: 
      member this.FindPaketNodes(name) = 
          [
              for node in this.Document |> getDescendants name do
                  let isPaketNode = ref false
                  for child in node.ChildNodes do
                          if child.Name = "Paket" then isPaketNode := true
  