public static void main(String[] args) {
		System.out.println(fill(new ArrayList<String>()));
		System.out.println(fill(new LinkedList<String>()));
		System.out.println(fill(new HashSet<String>()));
		System.out.println(fill(new TreeSet<String>()));
		System.out.println(fill(new LinkedHashSet<String>()));
		System.out.println(fill(new HashMap<String, String>()));
		System.out.println(fill(new TreeMap<String, String>()));
		System.out.println(fill(new LinkedHashMap<String, String>()));
	}