// buy / sell / exchange
if (shop instanceof BuyShop) {
event = new ShowCasePlayerSellEvent(player, (BuyShop)shop, quantity);
} else if (shop instanceof SellShop) {
event = new ShowCasePlayerBuyEvent(player, (SellShop)shop, quantity);
} else if (shop instanceof ExchangeShop) {
event = new ShowCasePlayerExchangeEvent(player, (ExchangeShop)shop, quantity);
} else if (shop instanceof DisplayShop) {