class Animal {
   public void move() {
      System.out.println("Animals can not speak");
   }
}
class Dog extends Animal {
   public void move() {
      super.move(); // invokes the super class method
      System.out.println("Dogs can be dangerous ");
   }
}
public class TestDog {
   public static void main(String args[]) {
      Animal b = new Dog(); // Animal reference but Dog object
      b.move(); // runs the method in Dog class
   }
}