/**
* @param amount Amount entered for buying operation
* @return change
* <p>This method calls the 'CancelBuy' method in the VendingMachine class.
*/
public double CancelBuy(double amount) {
double change;
VendingMachine machine = parentUI.getVendingMachine();
change = machine.CancelBuyOperation(amount); // Call to the method in Vending Machine Class
return change;
}
