anchor.diff:  open Fable.Import.vscode
   open Fable.Import.Node
   open Fable.Core.JsInterop
  -
   open DTO
   open Ionide.VSCode.Helpers
   
   module CodeLens =
  -    let mutable cache = None
  +    let mutable cache: Map<string, CodeLens[]> = Map.empty
   
       let private createProvider () =
           let symbolsToCodeLens (doc : TextDocument) (symbols: Symbols[]) : CodeLens[] =
  
positive.code:                     let data = symbolsToCodeLens doc result.Data
                      let d =
                          if data.Length > 0 then
                              cache <- Some data
                              data
                          else
                              defaultArg cache [||]
  
  
                      return ResizeArray d
                  } |> Case2
  
negative.code:         }
  
      let activate selector (disposables: Disposable[]) =
          languages.registerCodeLensProvider(selector, createProvider()) |> ignore
          ()
  