**JAVA JUNIT AND MOCKITO ONLY **

Trainees have 1 hour to use TDD to write appropriate tests and the implementing code to meet the below requirements. The implementing classes must implement the appropriate service interface provided. Trainees are provided with two interface files: . . GradeCalculator You should create a class. To be successful, the method in the implementing class must return the appropriate String value when a double representing a mark is passed in. They are as follows: "fail when less than 75. "pass" when greater than or equal to 75 but less than 80. "merit when greater than or equal to 80 but less than 90. "distinction when greater than or equal to 90 but less than or equal to 100. GroupController Service o You should create a class. To be successful, the methods in the implementing class must meet the requirements specified below (you will require some mock objects to fully test): The getAll Trainees() method should return the Map of type returned by the readGroup() method of the DatabaseReader class (you should use the class provided and do not need to implement the database reader's methods). The remove TraineeByUsername() method should pass the trainee to be removed to the delete Trainee ByUsername() method of the DatabaseWriter class (you should use the class provided and do not need to implement the database writer's methods). The addTrainee() method should pass the trainee to be added to the DatabaseWriter's addTrainee() method (you should use the class provided and do not need to implement the database writer's methods)