For implementation purposes, you will create two separate customers, one local and one expatriate. The local has a saving account, and the expatriate has a loan account. Each customer is authorized to update her account in terms of deposits and withdrawals. At the end of each month, you application shows the following per customer:
1. The current balance after all the deposits and withdrawals.
2. For a saving account, the interest-based amount to add to the balance.
3. For a loan account, the interest-based amount to deduct from the balance