return new Builder<>();
  }

  /**
   * Returns a new builder with a hint for how many distinct keys are expected to be added. The
   * generated builder is equivalent to that returned by {@link #builder}, but may perform better if
   * {@code expectedKeys} is a good estimate.
   *
   * @throws IllegalArgumentException if {@code expectedKeys} is negative
   * @since 33.3.0
   */

   * MoreExecutors#directExecutor}. Otherwise, avoid it: See the warnings on the docs for {@code
   * directExecutor}.
   *
   * <p>This is the most general listener interface. For common operations performed using
   * listeners, see {@link Futures}. For a simplified but general listener interface, see {@link
   * Futures#addCallback addCallback()}.
   *

   * element). Note that for an {@link Object#equals}-based multiset, this gives the same result as
   * {@link Collections#frequency} (which would presumably perform more poorly).
   *
   * <p><b>Note:</b> the utility method {@link Iterables#frequency} generalizes this operation; it
   * correctly delegates to this method when dealing with a multiset, but it can also accept any

    awaitDone(
        new FinalizationPredicate() {
          @Override
          public boolean isDone() {
            return ref.get() == null;
          }
        });
  }

  /**
   * Tries to perform a "full" garbage collection cycle (including processing of weak references and
   * invocation of finalize methods) and waits for it to complete. Ensures that at least one weak

     */
    fun settings(settings: Settings) =
      apply {
        this.settings.clear()
        this.settings.merge(settings)
      }

    /**
     * Attempts to perform a web socket upgrade on the connection.
     * This will overwrite any previously set status, body, or streamHandler.
     */
    fun webSocketUpgrade(listener: WebSocketListener) =
      apply {

      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
      copyright license to reproduce, prepare Derivative Works of,
      publicly display, publicly perform, sublicense, and distribute the
      Work and such Derivative Works in Source or Object form.

   3. Grant of Patent License. Subject to the terms and conditions of

      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
      copyright license to reproduce, prepare Derivative Works of,
      publicly display, publicly perform, sublicense, and distribute the
      Work and such Derivative Works in Source or Object form.

   3. Grant of Patent License. Subject to the terms and conditions of

      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
      copyright license to reproduce, prepare Derivative Works of,
      publicly display, publicly perform, sublicense, and distribute the
      Work and such Derivative Works in Source or Object form.

   3. Grant of Patent License. Subject to the terms and conditions of

	reader, err := sanitizePolicy(r)
	if err != nil {
		return PostPolicyForm{}, err
	}

	d := json.NewDecoder(reader)

	// Convert po into interfaces and
	// perform strict type conversion using reflection.
	var rawPolicy struct {
		Expiration string        `json:"expiration"`
		Conditions []interface{} `json:"conditions"`
	}

	d.DisallowUnknownFields()

      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
      copyright license to reproduce, prepare Derivative Works of,
      publicly display, publicly perform, sublicense, and distribute the
      Work and such Derivative Works in Source or Object form.

   3. Grant of Patent License. Subject to the terms and conditions of