Typeinfo exercise 15  * Exercise 15: (4) Implement a new PetCreator using Registered Factories,
 * and modify the Pets Facade so that it uses this one instead of the other two. 
 * Ensure that the rest of the examples that use Pets .Java still work correctly.
 * 
 * We have two PetCreator, one is PetCreator.java, another is LiteralPetCreator. Add one new PetCreator
 */
//No need to implements a indivual interface, use Factory.java in package factory.
//For exercise 15, petsList and method randomPet is the correct answer, but there is a Illegal exception need to research