anchor.diff:          <| {defOvrd with PostRestart = postRestart}
       actor <! "restart"
       let response = actor <? "msg" |> Async.RunSynchronously
  -    system.Shutdown()
  -    system.AwaitTermination()
  +    system.Terminate() |> ignore
  +    system.WhenTerminated.Wait(TimeSpan.FromSeconds(2.)) |> ignore
       (!postRestartCalled, response) |> equals (true, "msg")
positive.code:         <| {defOvrd with PreRestart = preRestart}
      actor <! "restart"
      let response = actor <? "msg" |> Async.RunSynchronously
      system.Shutdown()
      system.AwaitTermination()
      (!preRestartCalled, response) |> equals (true, "msg")
  
  [<Fact>]
  
negative.code:         <| {defOvrd with PostStop = postStop}
      actor <! PoisonPill.Instance
      system.Stop(actor)
      system.Terminate() |> ignore
      system.WhenTerminated.Wait(TimeSpan.FromSeconds(2.)) |> ignore
      (!postStopCalled) |> equals (true)
  
  [<Fact>]
  