anchor.diff:     static member StartImmediate(workflow:Async<unit>, ?cancellationToken) =
         let token = defaultArg cancellationToken { Cell = None }
         let (Cont f) = workflow
  -      let aux = { ExceptionCont = ignore; CancelledCont = ignore; CancellationToken = token }
  +      let aux = { StackCounter = ref 0; ExceptionCont = ignore; 
  +                  CancelledCont = ignore; CancellationToken = token }
         f { Cont = ignore; Aux = aux }
   
      static member Sleep(milliseconds:int) = 
  
positive.code:       token.Cell.Value := true
  
  type AsyncParamsAux =
     { ExceptionCont : string -> unit
       CancelledCont : string -> unit 
       CancellationToken : CancellationToken }
  
  
negative.code: 
  let async = AsyncBuilder()
  
  type Async =
     static member FromContinuations(f) = protectedCont <| fun k ->
        f (k.Cont, k.Aux.ExceptionCont, k.Aux.CancelledCont)
  