addAll(set, elements);
    return set;
  }

  public static <E extends @Nullable Object> Set<E> copyToSet(E[] elements) {
    return copyToSet(Arrays.asList(elements));
  }

  // Would use Maps.immutableEntry
  public static <K extends @Nullable Object, V extends @Nullable Object> Entry<K, V> mapEntry(
      K key, V value) {
    return Collections.singletonMap(key, value).entrySet().iterator().next();
  }

    addAll(set, elements);
    return set;
  }

  public static <E extends @Nullable Object> Set<E> copyToSet(E[] elements) {
    return copyToSet(Arrays.asList(elements));
  }

  // Would use Maps.immutableEntry
  public static <K extends @Nullable Object, V extends @Nullable Object> Entry<K, V> mapEntry(
      K key, V value) {
    return Collections.singletonMap(key, value).entrySet().iterator().next();
  }