/// <summary>
/// executes the trade if IsClosed flag indicates a closed trade, should only be called after buyer confirmation
/// </summary>
public void MakeTrade()
{
if (IsClosed == true)
{
TradeDate = DateTime.UtcNow;
Buyer.AddCardToInventory(OfferCard);
Offerer.AddCardToInventory(BuyerCard);
Buyer.RemoveCardFromInventory(BuyerCard);
Offerer.RemoveCardFromInventory(OfferCard);
}
else
{
throw new Exception("trade is not closed.");
}
}