anchor.diff:  type TestHostWorkspaceServices(hostServices: HostServices, workspace: Workspace) as this =
       inherit HostWorkspaceServices()
   
  +    let exportProvider = createExportProvider()
  +
       let services1 =
           exportProvider.GetExports<IWorkspaceService, TestWorkspaceServiceMetadata>()
   
  
positive.code:         |> Seq.append MefHostServices.DefaultAssemblies
          |> Array.ofSeq
  
      let exportProvider =
          let resolver = Resolver.DefaultInstance
          let catalog = 
              let asms = getAssemblies()
  
negative.code:                             //"Microsoft.CodeAnalysis.LanguageServer.Protocol.dll"
                             // "Microsoft.CodeAnalysis.Features.dll"
                              "Microsoft.CodeAnalysis.Workspaces.dll"
                             // "Microsoft.CodeAnalysis.EditorFeatures.dll"
                            //  "Microsoft.CodeAnalysis.CSharp.EditorFeatures.dll"
                            //  "Microsoft.CodeAnalysis.EditorFeatures.Text.dll"
  