overload_parent.java

public class HelloWorld
{
  public static void main(String[] args)
  {
    A b = new B();
    foo(b);
    A a = new A();
    foo(a);
    B really_b = new B();
    foo(really_b);
  }
  
  private static void foo (A arg) {
    System.out.println("Aaaa");
  }
  private static void foo (B arg) {
    System.out.println("Beee");
  }
}

class A {}
class B extends A {}