Unit tests for Generic Methods

When Visual Studio generates a unit test for a generic class, such as MyList<T>, it generates two methods: a generic helper and a test method. If MyList<T> has one or more type constraints, the type argument must satisfy all the type constraints. To make sure that the generic code under test works as expected for all permissible inputs, the test method calls the generic helper method with all the constraints that you want to test

http://msdn.microsoft.com/en-us/library/ms243176.aspx