Container exercise 4,  * Exercise 4: (3) Create a generator class that produces character names (as String
objects) from your favorite movie (you can use Snow White or Star Wars as a fallback) each
time you call next( ),// here we use star wars
* and loops around to the beginning of the character list when it runs out
of names. 
* Use this generator to fill an array, an ArrayList, a LinkedList, a HashSet, a
LinkedHashSet, and a TreeSet, then print each container.(Work: This means generator will fill a container)
* print(ExerciseFour.Generator.fill(new ArrayList<String>()));//contain the elements with inserted orders
        print(ExerciseFour.Generator.fill(new LinkedList<String>()));//contain the elements with inserted orders, has many other functions
        print(ExerciseFour.Generator.fill(new HashSet<String>()));//store the elements without duplicate elements, very fast storage, but order is disobey
        print(ExerciseFour.Generator.fill(new TreeSet<String>()));// Also keeps the objects in ascending comparison order, also store the elements without duplicate elements
        print(ExerciseFour.Generator.fill(new LinkedHashSet<String>()));//keeps the objects in the order in which they were added