public virtual int _GetUniqueIdentifier() { var hashCode = 399326290; hashCode = hashCode * -1521134295 + (Id?.GetHashCode() ?? 0); hashCode = hashCode * -1521134295 + (DateOfStockUpdate?.GetHashCode() ?? 0); hashCode = hashCode * -1521134295 + (DailyProduction?.GetHashCode() ?? 0); hashCode = hashCode * -1521134295 + (Stock?.GetHashCode() ?? 0); return(hashCode); }