This is an in-class group exercise based on homework 3. In homework 3, you used a TDD process to extend the Calc class. Now we are going to outline the addition of one more feature to Calc, and explore the ramifcations in small groups, and as a class. You will do one step at a time in your small groups. Then we will discuss the step as a class before continuing.

1. Create a user story to allow users to save a value in memory.
   
   
2. Outline one TDD test for the user story. (By “outline,” I mean write down the essential statements, but without a full JUnit structure.)
   
   
3. Talk about what needs to be changed in the Calc class for that test. (Don’t implement the changes.)
   
   
4. Repeat steps 2 & 3 until we are satisfied.
   
   
5. What refactoring is needed?