anchor.diff:      ]
   
       let shouldRetry exn = isMonoRuntime && iTry < nTries && (getExceptionNames exn |> List.contains "MonoBtlsException")
  -    
  +
       async {
           try
               let uri = Uri url
  
positive.code:     /// Check if 'text' starts with the 'prefix' string case insensitive
      let inline startsWithIgnoreCase (prefix:string) (text:string) =
          text.IndexOf(prefix, StringComparison.OrdinalIgnoreCase) = 0
      
      /// Match if 'text' starts with the 'prefix' string case insensitive
      let (|StartsWithIC|_|) (prefix:string) (text:String) =
          if startsWithIgnoreCase prefix text then Some () else None
      
      /// Check if 'text' ends with the 'suffix' string case insensitive
      let inline endsWithIgnoreCase (suffix:string) (text:string) =
          suffix.Length <= text.Length &&
          text.LastIndexOf(suffix, StringComparison.OrdinalIgnoreCase) >= text.Length - suffix.Length
      
      /// Match if 'text' ends with the 'suffix' string case insensitive
      let (|EndsWithIC|_|) (suffix:string) (text:String) =
          if endsWithIgnoreCase suffix text then  Some () else None
  
      let quoted (text:string) = (if text.Contains(" ") then "\"" + text + "\"" else text) 
  
      let inline trim (text:string) = text.Trim()
      let inline trimChars chs (text:string) = text.Trim chs
  
negative.code:             { new IObservable<'a> with
                  member __.Subscribe obs =
                      let cts = new CancellationTokenSource()
                      let sub =
                          input.Subscribe
                            ({ new IObserver<#seq<'a>> with
                                member __.OnNext values = values |> Seq.iter obs.OnNext
                                member __.OnCompleted() =
                                  cts.Cancel()
                                  obs.OnCompleted()
                                member __.OnError e =
                                  cts.Cancel()
                                  obs.OnError e })
  
                      { new IDisposable with
                          member __.Dispose() =
                              sub.Dispose()
                              cts.Cancel() }}
  
  