merge iterator test

Iterator<Integer> iterator = Arrays.asList(0,3,6,9).iterator();
Iterator<Integer> iterator1 = Arrays.asList(1,4,7,10).iterator();
Iterator<Integer> iterator2 = Arrays.asList(2,5,8,11).iterator();

List<Iterator<Integer>> myList = Arrays.asList(iterator, iterator1, iterator2);

MergeIterator mergeIterator = new MergeIterator(myList);