In Sections 22.4––22.6, we performed the first few steps in the object-oriented design of our ATM system. In Section 22.4, we identified the classes that we’ll need to implement and we created our first class diagram. In Section 22.5, we described some attributes of our classes. In Section 22.6, we examined object states and modeled object state transitions and activities. Now, we determine some of the class operations (or behaviors) needed to implement the ATM system.