Exercise using inheritance

• Introduce a subclass of Account called Checking, which has an attribute overdraftMaximum and overrides the withdraw method of Account so that it checks whether the amount to be withdrawn exceeds the balance by more than overdraftMaximum; if so, it does not perform the withdrawal; otherwise, it performs the withdrawal. For example, if the balance is 100.00, and the account is a regular account (no overdraft protection), then the account holder can withdraw up to 100.00; if the balance is 100.00, and the account has overdraft protection with an overdraft maximum of 50.00, then the account holder can withdraw up to 150.00.
• Test using JUnit.