anchor.diff:                  |> Async.AwaitTaskCorrect
                   |> Async.Ignore
   
  -        with :? QueueDoesNotExistException -> ()
  +        with QueueNotFoundException -> ()
       }
   
       member client.QueueNameExists (queueName : string) = async {
  
positive.code: 
          match res with
          | Choice1Of2 res -> return Some res.QueueUrl
          | Choice2Of2 (:? QueueDoesNotExistException) -> return None
          | Choice2Of2 exn -> return! Async.Raise exn
      }
  
  
negative.code: 
      // SQS limits you to up to 20 seconds of long polling wait time
      let maxWaitTime = TimeSpan.FromSeconds 20.
  
  [<AutoOpen>]
  module private SqsUtils =
  
      let (|QueueNotFoundException|_|) (e : Exception) =
          match e with
          | :? QueueDoesNotExistException -> Some ()
          | :? AmazonSQSException as e when e.Message.Contains "queue does not exist" -> Some ()
          | _ -> None
  
  [<Sealed; AutoSerializable(false)>]
  type SqsDequeueMessage internal (account : IAmazonSQS, queueUri : string, message : Message) =
  