Create a design class diagram for representing a vending machine. Assume all attributes (properties) and methods to be public. Assign the methods included in your design, the parameters and return types that you think are appropriate. The vending machine offers the following functionality: display message, process money, select item, dispense selected item, and return change. A vending machine holds items of the following types: drink, chocolate, and potato chips. Each item has a price, a description, and a shelf location. An item provides methods for getting and setting each of its attributes. Drinks specify their level of sugar, a chocolate item specifies the type of chocolate from which it is made (e.g., dark or white), and potato chips items specify if they are baked or fried. A vending machine can be used by two different types of users, namely customers and technicians. Each user has a list of functionalities that he or she can access. A technician has a user name and a password that permit him or her to access the vending machines technical functionality. On the other hand a customer has an attribute called mode, which specifies if the vending machine should run in an express or an advanced mode