Complete the Course class by implementing the courseSize$()$ method, which returns the total number of students in the course.

Given classes:

Class LabProgram contains the main method for testing the program.

Class Course represents a course, which contains an ArrayList of Student objects as a course roster. $($Type your code in here.$)$

Class Student represents a classroom student, which has three fields: first name, last name, and GPA.

Note: For testing purposes, different student values will be used.