code: public static <E> Set<E> newConcurrentHashSet(Iterable<? extends E> elements) {
      Set<E> set = newConcurrentHashSet();
      Iterables.addAll(set, elements);
      return set;
    }
docs: Creates a thread-safe set backed by a hash map and containing the given elements. The set is
  backed by a {@link ConcurrentHashMap} instance, and thus carries the same concurrency
  guarantees.
  
  <p>Unlike {@code HashSet}, this class does NOT allow {@code null} to be used as an element. The
  set is serializable.
  
  @param elements the elements that the set should contain
  @return a new thread-safe set containing those elements (minus duplicates)
  @throws NullPointerException if {@code elements} or any of its contents is null
  @since 15.0