Step 5. Defining whether to Mock Virtual and Non-Virtual Methods
By default, Typemock Isolator mocks both virtual and non-virtual methods. However, in some cases (for example, when you practice a Test-Driven Development approach), you might need to instruct Typemock Isolator to mock virtual methods only.
You define whether you want Typemock Isolator to mock any methods or only virtual methods by using the Design property of the [Isolated] attribute. You can the Design property at any level where you use the [Isolated] attribute.