Java Utililty Methods List Sort

if (comparator == null) {
    comparator = new Comparator() {
        public int compare(Object o1, Object o2) {
            return o1.toString().compareToIgnoreCase(o2.toString());
    };
Collections.sort(list, comparator);
...

if (list == null || list.isEmpty()) {
    return;
Collections.sort(list, comparator);

return list2.size() - list1.size();

return sort(list, null);

Collections.sort(source, new Comparator<E>() {
    @Override
    public int compare(E o1, E o2) {
        return o1.ordinal() - o2.ordinal();
});
return source;

Collections.sort(listOfClassDataList, new Comparator<List<T>>() {
    @Override
    public int compare(List<T> o1, List<T> o2) {
        if (o1 == null && o2 == null) {
            return 0;
        if (o1 == null && o2 != null) {
            return -1;
...

Map<String, List<T>> map = new TreeMap<String, List<T>>();
for (List<T> list : lists) {
    Collections.sort(list);
    StringBuilder builder = new StringBuilder();
    for (T item : list) {
        builder.append(item.toString());
    map.put(builder.toString(), list);
...

Collections.sort(lists);
return lists;

if (list != null && list.size() > 0) {
    Collections.sort((List) list);
return list;