Utility Methods

• As mentioned before, some methods can be private, serving as utilities for other class methods.
• Utility methods thus are not part of the class's public interface, not intended for clients' use.
• In the accompanying applet, totalAnnualSales is intended only for use by the toString method: it's a utility method.
• As a GUI remark, the hide method is applied to 3 of the GUI components.

  It causes them to be hidden from the user, preventing the user from further interaction with them.