anchor.diff:  [<SupportsPeekRelationship "IsDefinedBy">]
   type PeekableItemSourceProvider
       [<ImportingConstructor>]
  -    (_peekResultFactory: IPeekResultFactory,
  -     _textDocumentFactoryService: ITextDocumentFactoryService,
  -     _serviceProvider: System.IServiceProvider) =
  -//     projectFactory: ProjectFactory,
  -//     vsLanguageService: VSLanguageService) =
  -
  -    do System.Diagnostics.Debug.Fail "PeekableItemSourceProvider ctor"
  +    (peekResultFactory: IPeekResultFactory,
  +     textDocumentFactoryService: ITextDocumentFactoryService,
  +     [<Import(typeof<SVsServiceProvider>)>] serviceProvider: System.IServiceProvider,
  +     projectFactory: ProjectFactory,
  +     vsLanguageService: VSLanguageService) =
   
       interface IPeekableItemSourceProvider with
  -        member __.TryCreatePeekableItemSource(_buffer: ITextBuffer) =
  -            do System.Diagnostics.Debug.Fail "Getting text doc..."
  -            null
  -//            match textDocumentFactoryService.TryGetTextDocument buffer with
  -//            | true, doc ->
  -//                do System.Diagnostics.Debug.Fail "Got doc, creating source provider..."
  -//                buffer.Properties.GetOrCreateSingletonProperty(
  -//                    fun() -> 
  -//                        upcast new PeekableItemSource(buffer, doc, peekResultFactory,
  -//                                                      serviceProvider, projectFactory, vsLanguageService))
  -//            | _ -> null+        member __.TryCreatePeekableItemSource(buffer: ITextBuffer) =
  +            match textDocumentFactoryService.TryGetTextDocument buffer with
  +            | true, doc ->
  +                buffer.Properties.GetOrCreateSingletonProperty(
  +                    fun() -> 
  +                        upcast new PeekableItemSource(buffer, doc, peekResultFactory,
  +                                                      serviceProvider, projectFactory, vsLanguageService))
  +            | _ -> null
positive.code: open System.ComponentModel.Composition
  open Microsoft.VisualStudio.Language.Intellisense
  open Microsoft.VisualStudio.Text
  open Microsoft.VisualStudio.Utilities
  open Microsoft.VisualStudio.Shell.Interop
  open FSharpVSPowerTools
  
negative.code:                             peekResultFactory.Create(
                                                  displayInfo, 
                                                  filePath, 
                                                  range.StartLine - 1,
                                                  range.StartColumn,
                                                  range.EndLine - 1,
                                                  range.EndColumn,
                                                  span.StartLine.LineNumber,
                                                  span.StartColumn,
                                                  true)
  
                          resultCollection.Add result
      //                callback.ReportProgress(100 * ++processedSourceLocations / sourceLocations.Count);
              }
  
  