code: public static void shuffle(final List<?> list) {
      if (list == null) {
        throw new IllegalArgumentException("list");
      }
      synchronized (list) {
        Collections.shuffle(list, random);
      }
    }
docs: Shuffles a list (in-place).
  
  The list is shuffled using the global random generator offered by Jazz.
  
  @since 1.0.0
  @param list
  The list to shuffle. Note that the list needs to be modifiable
  since it is shuffled in-place.
  @throws IllegalArgumentException
  If the given <code>list</code> was null.