List<Integer>numbers = Arrays.asList(1,2,2,2,3,5); // [1, 2, 3, 5]
System.out.println(numbers);
Set<Integer> hashSet = new LinkedHashSet(numbers);
ArrayList<Integer> removedDuplicates = new ArrayList(hashSet);
System.out.println(removedDuplicates); // [1, 2, 3, 5]