code: @GwtIncompatible // CopyOnWriteArraySet
    public static <E> CopyOnWriteArraySet<E> newCopyOnWriteArraySet(Iterable<? extends E> elements) {
      // We copy elements to an ArrayList first, rather than incurring the
      // quadratic cost of adding them to the COWAS directly.
      Collection<? extends E> elementsCollection =
          (elements instanceof Collection)
              ? Collections2.cast(elements)
              : Lists.newArrayList(elements);
      return new CopyOnWriteArraySet<E>(elementsCollection);
    }
docs: Creates a {@code CopyOnWriteArraySet} instance containing the given elements.
  
  @param elements the elements that the set should contain, in order
  @return a new {@code CopyOnWriteArraySet} containing those elements
  @since 12.0