*
   * <p>The iteration order of the returned map follows the enum's iteration order, not the order in
   * which the elements appear in the given map.
   *
   * @param map the map to make an immutable copy of
   * @return an immutable map containing those entries
   * @since 14.0
   */
  @GwtCompatible(serializable = true)
  public static <K extends Enum<K>, V> ImmutableMap<K, V> immutableEnumMap(
      Map<K, ? extends V> map) {

   */
  @VisibleForTesting
  CountDownLatch whenClosedCountDown() {
    return closeables.whenClosedCountDown();
  }

  /** The state of a {@link CloseableList}. */
  enum State {
    /** The {@link CloseableList} has not been subsumed or closed. */
    OPEN,

    /**
     * The {@link CloseableList} has been subsumed into another. It may not be closed or subsumed