These steps are the same for all exercises of the Introduction to Nested Test Classes lesson. In other words, before you start an exercise, make sure that you have finished these steps:
1. Clone the Git repository that contains the sample applications of this course. If you have already cloned that repository, you can ignore this step.
2.Open the project found from the introduction-to-junit5/introduction-to-junit5-test-classes/exercises/nested-test-class-exercise directory with your favorite IDE.
Remember to revert your changes after you have finished an exercise!