@Before
    //Initializing method create instances of customers, employee,
    //affiliate and initialize list of items
    public void init(){

        newCustomer = new Customer("NewCustomerId", "NewCustomerName", new Date());
        Calendar calendar = Calendar.getInstance();
        calendar.add(Calendar.YEAR, -2);
        oldCustomer = new Customer("OldCustomerId", "OldCustomerName", calendar.getTime());
        employee = new Employee("EmpId", "EmpName");
        affiliate = new Affiliate("AffiliateId", "AffiliateName");

        items = new ArrayList<Item>();
        items.add(new Item("GroceryItemId1", "GroceryItemName1", 10.0, ItemType.GROCERY));
        items.add(new Item("GroceryItemId2", "GroceryItemName2", 20.0, ItemType.GROCERY));
        items.add(new Item("GroceryItemId3", "GroceryItemName3", 30.0, ItemType.GROCERY));
        items.add(new Item("GroceryItemId4", "GroceryItemName4", 40.0, ItemType.GROCERY));
        items.add(new Item("NonGroceryItemId1", "NonGroceryItemName1", 10.0, ItemType.CLOTHING));
        items.add(new Item("NonGroceryItemId2", "NonGroceryItemName2", 20.0, ItemType.CLOTHING));
        items.add(new Item("NonGroceryItemId3", "NonGroceryItemName3", 30.0, ItemType.ELECTRONIC));
        items.add(new Item("NonGroceryItemId4", "NonGroceryItemName4", 40.0, ItemType.ELECTRONIC));
    }