anchor.diff:  
   open System.Collections.Generic
   
  +//[<AllowNullLiteral>]
   type MyListener(root:IBuildInformation) =
       let defaultTarget = root.AddBuildStep("no target", "no target", DateTime.UtcNow, BuildStepStatus.Unknown)
       let mutable target = defaultTarget
  
positive.code:                     target.FinishTime <- DateTime.UtcNow
                      target <- defaultTarget
  //                    root.Save()
  
  //listeners.Clear()
  //listeners.Add(MyListener())
  
negative.code: //    stB.Node.Children.AddBuildMessage("this is another bm for b", BuildMessageImportance.High, DateTime.UtcNow) |> ignore
      
  
      if isTfsBuild then
          tfsLogger.Save()
          
  
  //    bi.Save()
  )
  
  
  