anchor.diff:      ResolvedSourceFiles : ModuleResolver.ResolvedSourceFile list }
   
   type UpdateMode =
  -    | UpdatePackage of  GroupName * PackageName
  +    | UpdatePackage of GroupName * PackageName
       | UpdateGroup of GroupName
       | Install
       | UpdateAll
  
positive.code:             | true,Resolution.Conflict(_) -> tryToImprove true |> snd
              | _,x-> x
  
      match step (Map.empty, [], Set.empty, rootDependencies) with
      | Resolution.Conflict(_) as c -> c
      | Resolution.Ok model -> Resolution.Ok(cleanupNames model)
  
negative.code:                 let resolution =
                      selectedPackageVersions 
                      |> Seq.fold (fun map p -> Map.add p.Name p map) Map.empty
                      |> cleanupNames
  
                  Resolution.Ok(resolution)
              else
  