Explanation/Reference:
Explanation:
Step 1: Select the Purchasing Project and add a new Unit Test Project.
First we create a Unit Test Project within the current project.
Step 2:

You can turn an existing unit test into an ASP.NET unit test by configuring it, that is, by assigning values to certain of the test's custom attributes. You set these values in the code file that contains the unit test.
All unit tests require the [TestMethod] attribute.
Step 3: Build the solution
Step 4: Run all tests
Step 5: Debug the solution
After you run a unit test, if you chose to edit the test run configuration when you ran the test, you can open the Code Coverage window to see what percentage of the methods in the code that you are testing were covered by your unit tests.
Incorrect:
Not:

You do not set up testing by creating copies of methods.
References: https://msdn.microsoft.com/en-us/library/ms182526(v=vs.90).aspx