public override void Buy()
 {
     if (currency.SpendCurrency(currencyPrice))
     {
         if (OnPurchaseSucceeded != null)
         {
             OnPurchaseSucceeded.Invoke();
         }
     }
     else
     {
         if (OnPurchaseFailed != null)
         {
             OnPurchaseFailed.Invoke();
         }
     }
 }
 public void CompletePurchase()
 {
     if (currency.SpendCurrency(currencyPrice))
     {
         if (OnPurchaseSucceeded != null)
         {
             OnPurchaseSucceeded.Invoke();
         }
     }
     else
     {
         if (OnPurchaseFailed != null)
         {
             OnPurchaseFailed.Invoke();
         }
     }
 }