* under {@code directExecutor}: Not only might the wait for a lock be long, but if the running
   * thread was holding a lock, the listener may deadlock or break lock isolation.
   *
   * <p>This instance is equivalent to:
   *
   * <pre>{@code
   * final class DirectExecutor implements Executor {
   *   public void execute(Runnable r) {
   *     r.run();
   *   }
   * }

    return least(k, comparator.reversed());
  }

  /**
   * Returns the minimum of the two values. If the values compare as 0, the first is returned.
   *
   * <p>The recommended solution for finding the {@code minimum} of some values depends on the type
   * of your data and the number of elements you have. Read more in the Guava User Guide article on

  public static final String ORIGIN = "Origin";
  /**
   * The HTTP <a href="https://github.com/WICG/origin-isolation">{@code Origin-Isolation}</a> header
   * field name.
   *
   * @since 30.1
   */
  public static final String ORIGIN_ISOLATION = "Origin-Isolation";
  /** The HTTP {@code Proxy-Authorization} header field name. */
  public static final String PROXY_AUTHORIZATION = "Proxy-Authorization";

    // when deep chains of futures exist resulting in a StackOverflowException. We could detect
    // arbitrary cycles using a thread local but this should be a good enough solution (it is also
    // what jdk collections do in these cases)
    try {
      if (o == this) {
        builder.append("this future");
      } else {
        builder.append(o);
      }