android/guava/src/com/google/common/collect/Sets.java
public static <E> Set<E> newConcurrentHashSet(Iterable<? extends E> elements) {
    Set<E> set = newConcurrentHashSet();
    Iterables.addAll(set, elements);
    return set;
  }
public static <E> Set<E> newConcurrentHashSet(Iterable<? extends E> elements) {
    Set<E> set = newConcurrentHashSet();
    Iterables.addAll(set, elements);
    return set;
  }
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