public void set_Tag_Test_ReturnsTagIsTag()
        {
            // arrange
            var expenseItem = new ExpenseItem();

            // act
            expenseItem.Tag = "Tag";

            // assert
            // side affects on expenseItem
            Assert.AreEqual("Tag", expenseItem.Tag);
            Assert.AreEqual("<Item><ID>0</ID><Date></Date><Amount>0</Amount><Tag>Tag</Tag></Item>", expenseItem.ToXMLString());
            Assert.AreEqual("0, , 0, Tag", expenseItem.ToString());
        }
        public void set_ID_Test_ReturnsIDIs1()
        {
            // arrange
            var expenseItem = new ExpenseItem(1, "dateString", 1, "tag");

            // act
            expenseItem.ID = 0;

            // assert
            // No objects were changed by the method under test. Using default asserts.
            // side affects on expenseItem
            Assert.AreEqual(1, expenseItem.ID);
            Assert.AreEqual("<Item><ID>1</ID><Date>dateString</Date><Amount>1</Amount><Tag>tag</Tag></Item>", expenseItem.ToXMLString());
            Assert.AreEqual("1, dateString, 1, tag", expenseItem.ToString());
        }