public static void main (String [] args)
    {
        Student[] students = new Student[10];
        for (int i = 0; i < 10; i++) {
            students[i] = new Student(i);
        }
        HashMap<Integer, Student> sMap = buildMap(students);
        System.out.println("Students are:");
        for (int i = 0; i < 10; i++) {
            System.out.println(sMap.get(i));
        }
    }