Question#3: A client can have a bank account. The client can withdraw or deposit money into the bank account. There are two types of bank account: saving account and checking account. The way money can be withdrawn or deposited depends on the type of the bank account.

1. Draw a class diagram corresponding to the above situation. (2 points)
2. Draw a sequence diagram illustrating a call by the client to withdraw money from the bank account. The withdraw method shall only allow to withdraw if the account is not empty. (2 points)