code: public static <T> List<T> sort(List<T> list, Comparator<? super T> c) {
  		Collections.sort(list, c);
  		return list;
  	}
docs: 针对List排序，排序会修改原List
  
  @param <T> 元素类型
  @param list 被排序的List
  @param c {@link Comparator}
  @return 原list
  @see Collections#sort(List, Comparator)