put(closeable, executor);
          return;
        }
      }
      closeQuietly(closeable, executor);
    }

    /**
     * Returns a latch that reaches zero when this objects' deferred closeables have been closed.
     */
    CountDownLatch whenClosedCountDown() {
      if (closed) {
        return new CountDownLatch(0);
      }
      synchronized (this) {
        if (closed) {

 * guaranteed to be supported by all Java platform implementations.
 *
 * <p>Assuming you're free to choose, note that <b>{@link #UTF_8} is widely preferred</b>.
 *
 * <p>See the Guava User Guide article on <a
 * href="https://github.com/google/guava/wiki/StringsExplained#charsets">{@code Charsets}</a>.
 *
 * @author Mike Bostock
 * @since 1.0
 */

   *
   * <pre>{@code
   * final class DirectExecutor implements Executor {
   *   public void execute(Runnable r) {
   *     r.run();
   *   }
   * }
   * }</pre>
   *
   * <p>This should be preferred to {@link #newDirectExecutorService()} because implementing the
   * {@link ExecutorService} subinterface necessitates significant performance overhead.
   *
   * @since 18.0
   */

    /** The key of the configuration. e.g. displayName */
    String LDAP_ATTR_DISPLAY_NAME = "ldap.attr.displayName";

    /** The key of the configuration. e.g. preferredLanguage */
    String LDAP_ATTR_PREFERRED_LANGUAGE = "ldap.attr.preferredLanguage";

    /** The key of the configuration. e.g. departmentNumber */
    String LDAP_ATTR_DEPARTMENT_NUMBER = "ldap.attr.departmentNumber";

        /**
         * Returns the algorithm name, usually used as key, never {@code null} value. The name is a standard name of
         * algorithm (if applicable) or any other designator that is algorithm commonly referred with. Example: "SHA-1".
         */
        @Nonnull
        String getName();

        /**
         * Returns the file extension to be used for given checksum file (without leading dot), never {@code null}. The

   *
   * @since 21.0
   */
  public static <E> Collector<E, ?, ImmutableSet<E>> toImmutableSet() {
    return CollectCollectors.toImmutableSet();
  }

  /**
   * Returns the empty immutable set. Preferred over {@link Collections#emptySet} for code
   * consistency, and because the return type conveys the immutability guarantee.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */

  /**
   * The "base64url" encoding specified by <a
   * href="http://tools.ietf.org/html/rfc4648#section-5">RFC 4648 section 5</a>, Base 64 Encoding
   * with URL and Filename Safe Alphabet, also sometimes referred to as the "web safe Base64." (This
   * is the same as the base 64 encoding with URL and filename safe alphabet from <a
   * href="http://tools.ietf.org/html/rfc3548#section-4">RFC 3548</a>.)
   *

  @Beta // TODO: b/288085449 - Remove.
  public static <E> Collector<E, ?, ImmutableSet<E>> toImmutableSet() {
    return CollectCollectors.toImmutableSet();
  }

  /**
   * Returns the empty immutable set. Preferred over {@link Collections#emptySet} for code
   * consistency, and because the return type conveys the immutability guarantee.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */

  /**
   * The HTTP <a href="https://www.w3.org/TR/referrer-policy/">{@code Referrer-Policy}</a> header
   * field name.
   *
   * @since 23.4
   */
  public static final String REFERRER_POLICY = "Referrer-Policy";

  /**
   * Values for the <a href="https://www.w3.org/TR/referrer-policy/">{@code Referrer-Policy}</a>
   * header.
   *
   * @since 23.4
   */

    public static final String LABELS_DISPLAY_NAME = "{labels.displayName}";

    /** The key of the message: Preferred Language */
    public static final String LABELS_user_preferredLanguage = "{labels.user_preferredLanguage}";

    /** The key of the message: Preferred Language */
    public static final String LABELS_PREFERRED_LANGUAGE = "{labels.preferredLanguage}";

    /** The key of the message: Department Number */