private void SetPrice(out PriceVolume thePrice, IFIXGroup singleGroup)
 {
     int iVolume = singleGroup.get_AsNumber(FIXTagConstants.esFIXTagMDEntrySize);
     if (iVolume == 0)
     {
         thePrice = new PriceVolume(null, null);
     }
     else
         thePrice = new PriceVolume(iVolume, singleGroup.get_AsDouble(FIXTagConstants.esFIXTagMDEntryPx));
 }