GetHistory-fails-to-return-the-SecurityName

When performing a GetHistory operation, the ".SecurityName" is not present in the returned Bars object. For example, the second WriteToDebugLog line won't return Apple Computer. I'm running Build 21.

CODE:
      public override void Initialize(BarHistory bars)
        {
         WriteToDebugLog(bars.Symbol + ",  " + bars.SecurityName);
         BarHistory stock = GetHistory(bars, "AAPL");
         WriteToDebugLog(stock.Symbol + ",  " + stock.SecurityName);
      }