code: public final ImmutableList<T> toSortedList(Comparator<? super T> comparator) {
          return Ordering.from(comparator).immutableSortedCopy(this);
      }
docs: Returns an {@code ImmutableList} containing all of the elements from this {@code
  FluentIterable} in the order specified by {@code comparator}.  To produce an {@code
  ImmutableList} sorted by its natural ordering, use {@code toSortedList(Ordering.natural())}.