// make the class cat inherit from Animal
public class Cat extends Animal {
  // java requires an explicit constructor when the supertype awaits parameters in the constructor
  public Cat(String name) {
    // call supertype constructor
    super(name);
  }

  // override make_sound
  public void make_sound() {
    // optional: call the parent class function
    super.make_sound();

    // add additional functionality
    System.out.println("meow");
  }
}