anchor.diff:          |> Seq.distinctBy (fun x -> x.Key)
           |> System.Collections.Concurrent.ConcurrentDictionary
   
  -    let langServices = TestHostLanguageServices(this, LanguageNames.FSharp)
  +    let langServices = TestHostLanguageServices(this, LanguageNames.FSharp, exportProvider)
   
       override _.Workspace = workspace
   
  
positive.code:     static member CreateDocument (filePath, text: SourceText) =
          let isScript = String.Equals(Path.GetExtension(filePath), ".fsx", StringComparison.OrdinalIgnoreCase)
  
          let hostServices = TestHostServices()
          let workspace = new AdhocWorkspace(hostServices)
  
          let projId = ProjectId.CreateNewId()
          let docId = DocumentId.CreateNewId(projId)
  
negative.code:         |> Seq.append MefHostServices.DefaultAssemblies
          |> Array.ofSeq
  
      let createExportProvider() =
          let resolver = Resolver.DefaultInstance
          let catalog = 
              let asms = getAssemblies()
  