ok What is navigation visibility? What is affordance? What is a private attribute? Answer the following questions with respect to the diagram below: What kind of model is the diagram below an example of (include the name of the model and its purpose)? When during system development is this kind of model used? Customer Explain the information presented in the diagram (that is, what are the components of the diagram, and what does it tell us?). < < < > Shopping Cart < > getTotal()- -totalPrice- :Order < > getPrice()- -itemPrice- calculate Total() :Item List 4 major tasks undertaken during the implementation phase of the systems development life cycle.