Code: public class ArrayListDemo { public static void rotate(List<?> list) { if (list.size() == 0) return; list.add(list.remove(0)); } public static void main(String[] args) { ArrayListDemo ald=new ArrayListDemo(); List<String> demo=new ArrayList<String>(); demo.add("uk"); ald.rotate(demo); if(demo.size() > 1) { System.out.println("i know surely size >1"); }else { System.out.println("this cannot happen...size is 0"); } } }