anchor.diff:  type FSharpParsedDocument(fileName) = 
       inherit DefaultParsedDocument(fileName)
       member val Tokens = None with get,set
  -    member val AllSymbolUses = None with get,set
  +    member val AllSymbolsKeyed = Dictionary<_,_>() with get, set
   
   // An instance of this type is created by MonoDevelop (as defined in the .xml for the AddIn) 
   type FSharpParser() = 
  
positive.code:             cancellationToken = cancellationToken,
              computation = async {
              let shortFilename = Path.GetFileName fileName
  
              let curVersion = parseOptions.Content.Version
              let isObsolete =
  
negative.code:                 doc.Ast <- results
  
              doc.LastWriteTimeUtc <- try File.GetLastWriteTimeUtc(fileName) with _ -> DateTime.UtcNow
              LoggingService.LogDebug ("FSharpParser: returning ParsedDocument on {0}", shortFilename)
              return doc :> _})
  
  