2. Fill in the blanks in the programs below, or mark N/A if nothing is needed. /** * Classroom class represents all classrooms */ public class Classroom { private int num_students; public (int num_students) { num_students = num_students; } } /** PhysicsLab class is a special type of Classroom */ public { public static final int[] WEIGHTS = {10, 25, 50}; public { } public void setupExperiments(); }