AtPay.java

public class AtPay implements Payment {
    @Override
    public void debitUser() {
        System.out.println("Money deducted from user using AtPay");
    }

    @Override
    public void checkUserBalance() {
        System.out.println("User balance checked using AtPay");
    }

    @Override
    public void creditUser() {
        System.out.println("Account credited using AtPay");
    }
}