상속: Message
        async Task<OperationResult> Process(TestStateless msg, IOperationContext arg2)
        {
            if (msg.SleepDurationMs > 0)
                await Task.Delay(msg.SleepDurationMs);

            return OperationResult.Success;
        }
        async public Task<OperationResult> TestStateless(TestStateless msg)
        {
            if (msg.SleepDurationMs > 0)
                await Task.Delay(msg.SleepDurationMs);

            return OperationResult.Success;
        }
 async Task<OperationResult> Process(TestStateless msg, IOperationContext context)
 {
     using (BackendCallsTimer.NewContext())
         return await _actor.SendAsync<OperationResult>(msg, context);
 }
 async Task<OperationResult> OnTestStateless(TestStateless msg, IOperationContext context)
 {
     using (BackendCallsTimer.NewContext())
         return await _actor.TestStateless(msg);
 }