有一个简单的程序代码。在构造函数中，super()没有扩展到超类的调用，我不明白在这种情况下会发生什么？

public class Student {

    private String name;
    private int rollNum;

    Student(String name,int rollNum){
        super(); //I can not understand why super keyword here.
        this.name=name;
        this.rollNum=rollNum;
    }


    public static void main(String[] args) {

        Student s1 = new Student("A",1);
        Student s2 = new Student("A",1);

        System.out.println(s1.equals(s2));
    }

}