anchor.diff:          afterItemGroup.AddAfterSelf (import)
       cproj
   
  -let ConvertProjectContent (xproj : XDocument) (project : Project) (package2Files) =
  -    let nugetFiles = package2Files |> Seq.filter (fun (id, _) -> project.PackageReferences |> Seq.contains id)
  -                                   |> Seq.map (fun (_, files) -> files)
  -                                   // TODO: should be fold with Set.union probably
  -                                   |> Seq.concat
  -                                   |> set
  +let ConvertProjectContent (xproj : XDocument) (project : Project) (package2Files : Map<PackageRef, Set<AssemblyRef>>) =
  +    let usedPackage2Files = package2Files |> Map.filter (fun id _ -> project.PackageReferences |> Set.contains id)
  +    let nugetFiles = usedPackage2Files |> Map.toSeq
  +                                       |> Seq.map (fun (id, files) -> files)
  +                                       |> Seq.concat
  +                                       |> Set
   
       let convxproj = ConvertProject xproj project nugetFiles
       convxproj
   
  -let ConvertProjects (antho : Anthology) (package2Files) xdocLoader xdocSaver =
  +let ConvertProjects (antho : Anthology) (package2Files : Map<PackageRef, Set<AssemblyRef>>) xdocLoader xdocSaver =
       let wsDir = WorkspaceFolder ()
       for project in antho.Projects do
           let repoDir = wsDir |> GetSubDirectory (project.Repository.Print())
  
positive.code:     // for each package, get all assemblies
      let package2Files = antho.Packages 
                          |> Seq.map (fun x -> (x.Id, Package.GatherAllAssemblies x.Id))
  
      ConvertProjects antho package2Files XDocumentLoader XDocumentSaver
  
negative.code:         let projectFile = prjDir |> GetFile (AddExt (project.ProjectGuid.ToString("D")) Targets)
          xdocSaver projectFile content
  
  let ConvertProject (xproj : XDocument) (project : Project) (nugetFiles : Set<AssemblyRef>) =
      let filterProject (xel : XElement) =
          let attr = !> (xel.Attribute (NsNone + "Project")) : string
          attr.StartsWith(MSBUILD_PROJECT_FOLDER, StringComparison.CurrentCultureIgnoreCase)
  