private void LookupStockPrice(RefreshStockPriceMessage message)
        {
            var latestPrice = StockPriceServiceGateway.GetLatestPrice(message.StockSymbol);

            //response
            Sender.Tell(new UpdatedStockPriceMessage(latestPrice, DateTime.Now));
        }
 Create(IStockPriceServiceGateway stockPriceServiceGateway)
 {
     return(Agent.Start <RefreshStockPriceMessage, UpdatedStockPriceMessage>(message =>
     {
         var latestPrice = stockPriceServiceGateway.GetLatestPrice(message.StockSymbol);
         return new UpdatedStockPriceMessage(latestPrice, DateTime.Now);
     }));
 }