public StopReceivingResult Append(StopReceivingResult result) =>
 _exceptions.Match(
     some: exceptions =>
     new StopReceivingResult(
         result._exceptions
         .Match(
             some: rExceptions => exceptions.AddRange(rExceptions),
             none: () => exceptions)),
     none: () => result);
 public static StopReceivingResult Append(this StopReceivingResult self, Either <Exception, Unit> next) =>
 self.Append(new StopReceivingResult(next));