/** Instances are animals with name and age */
public class Animal {
   private String name; // Cannot be empty.
   private int age;     // Must be >= 0
   
   /** Constructor: instance of animal with name, age
     * Precondition: n not null, empty
     *               age >= 0
     */
   public Animal(String n, int a) {
       name = n;
       age = a;
   }
   
   
   public Animal() {
   }
   
   /** Yields Animal name */
   public String getName() {
       return name;
   }
 
   /** Yields Animal age */
   public int getAge() {
       return age;
   }
   
   /** Yields: "a is older than this animal" */
   public boolean isOlder(Animal a) {
       return a.age > age;
   }

   /** Yields: String representation of this object */
   public String toString() {
       return name+" (Animal, age "+age+")";
   }
  
   /** Yields: Òh is an Animal with the same       
     * values in its fields as this Animal 
     */   
   public boolean equals(Object h) {   
       if (!(h instanceof Animal)) { 
           return false;
       }         
       
       Animal ob= (Animal)h;      
       return name.equals(ob.name) && age == ob.age;  
   } 
   
     public static double checkWght(Animal h) { 
         Cat c = (Cat)h;    // Downward cast  
         return c.getWeight();
     }
         
}