class Cat extends Animal {   // A Cat "is-a" Animal.

  double clawSharpness;  // 0.0 represents dull; 1.0 is razor-sharp.

  /** Constructor
   * @param nom, the cat's name.
   */
  public Cat( String nom ) {
    super( nom, "meow" );  // Call the superclass's constructor.
    this.clawSharpness = 0.9;  // Kittens start out with sharp claws.
    }

  // A method specific to cats, not shared by all Animals:
  /** What happens, when a cat pounces.
   * @return The sound of this cat pouncing.
   */
  String pounce() {
    // Every time they pounce, the claws get 10% closer to perfect sharpness:
       this.clawSharpness += 0.1*(1-this.clawSharpness);
    return "whoooomf";
    }    
    
  }