Class Responsibility calculate FinalGrade CourseCalculator Category Description The main class of our application. Interacts with the user to get input and ensure that it is valid Calculates the final grade for the course The parent class of MultiGrade and SingleGrade Stores data for grade items which uses multiple grades. These grades can be averaged together (and are equally weighted) to generate a grade for the course. (For example, quizzes or assignments) MultiGrade Calculate a grade for the grade item SingleGrade Return a grade for the grade item Stores data for grade items which consist of a single grade. (For example, participation or project marks) Finally, draw a class diagram with all four classes. Include any instance variables and methods with appropriate access modifiers (and for the methods, arguments and return values). Ensure that relationships between classes are appropriately depicted, and that any classes or methods which are abstract are clearly indicated