In Java 15,

import java.io.; import java.util.;

class Arithmetic {

int add(int a, int b) {
    return a+b;
}

}

class Adder extends Arithmetic {

}

public class Solution {

public static void main(String[] args) {
    Adder adder = new Adder();
    System.out.println("My superclass is: " + adder.getClass().getGenericSuperclass().getTypeName());

    System.out.println(adder.add(30,12) + " " + adder.add(10,3) + " " + adder.add(15,5));
}

}