anchor.diff:                      let! y = f2 4
                       return ()
                   with
  -                | e -> data := e.Message
  +                | e -> data := e.Message.Trim('"')
               } 
               |> Async.StartImmediate
           f()
  
positive.code:                 do! f()
                  return ()
              with
              | e -> data := !data + e.Message
          } 
          |> Async.StartImmediate
          do! Async.Sleep 100
  
negative.code: let ``Async.Catch works``() =
      let assign res = function
          | Choice1Of2 msg -> res := msg
          | Choice2Of2 (ex: Exception) -> res := "ERROR: " + ex.Message.Trim('"')
      let res1 = ref ""
      let res2 = ref ""
      async {
  