public PurchaseProcessingResult ProcessPurchase(PurchaseEventArgs args)
    {
        // A consumable product has been purchased by this user.
        if (String.Equals(args.purchasedProduct.definition.id, PRODUCT_50_GEMS, StringComparison.Ordinal))
        {
            Debug.Log(string.Format("ProcessPurchase: PASS. Product: '{0}'", args.purchasedProduct.definition.id));
            // The consumable item has been successfully purchased, add 100 coins to the player's in-game score.
            Currency.AddGems(50);
        }
        // Or ... an unknown product has been purchased by this user. Fill in additional products here....
        else
        {
            Debug.Log(string.Format("ProcessPurchase: FAIL. Unrecognized product: '{0}'", args.purchasedProduct.definition.id));
        }

        // Return a flag indicating whether this product has completely been received, or if the application needs
        // to be reminded of this purchase at next app launch. Use PurchaseProcessingResult.Pending when still
        // saving purchased products to the cloud, and when that save is delayed.
        return(PurchaseProcessingResult.Complete);
    }