* who can't use Java 8, or who want an API more focused than {@code CompletableFuture}. (If you
 * need to adapt between {@code CompletableFuture} and {@code ListenableFuture}, consider <a
 * href="https://github.com/lukas-krecan/future-converter">Future Converter</a>.)
 *
 * <h3>Extension</h3>
 *
 * If you want a class like {@code FluentFuture} but with extra methods, we recommend declaring your

  // * Future completion can be observed if the waitersField field contains a TOMBSTONE

  // Timed Get
  // There are a few design constraints to consider
  // * We want to be responsive to small timeouts, unpark() has non trivial latency overheads (I
  //   have observed 12 micros on 64-bit linux systems to wake up a parked thread). So if the

   * the given class. If the object being tested is {@code null} this predicate evaluates to {@code
   * false}.
   *
   * <p>If you want to filter an {@code Iterable} to narrow its type, consider using {@link
   * com.google.common.collect.Iterables#filter(Iterable, Class)} in preference.
   *
   * <p><b>Warning:</b> contrary to the typical assumptions about predicates (as documented at

    /** Executor service for concurrent search operations across multiple searchers */
    protected ExecutorService executorService;

    /** Size of the window for rank fusion processing, determines how many results to consider */
    protected int windowSize;

    /** Set of available searcher names that can be used for search processing */
    protected Set<String> availableSearcherNameSet;

    /**

      return Optional.of(list.get(list.size() - 1));
    }
    Iterator<E> iterator = iterable.iterator();
    if (!iterator.hasNext()) {
      return Optional.absent();
    }

    /*
     * TODO(kevinb): consider whether this "optimization" is worthwhile. Users with SortedSets tend
     * to know they are SortedSets and probably would not call this method.
     */
    if (iterable instanceof SortedSet) {

      return Optional.of(list.get(list.size() - 1));
    }
    Iterator<E> iterator = iterable.iterator();
    if (!iterator.hasNext()) {
      return Optional.absent();
    }

    /*
     * TODO(kevinb): consider whether this "optimization" is worthwhile. Users with SortedSets tend
     * to know they are SortedSets and probably would not call this method.
     */
    if (iterable instanceof SortedSet) {

  private var intervalPongsReceived = 0L
  private var degradedPingsSent = 0L
  private var degradedPongsReceived = 0L
  private var awaitPingsSent = 0L
  private var awaitPongsReceived = 0L

  /** Consider this connection to be unhealthy if a degraded pong isn't received by this time. */
  private var degradedPongDeadlineNs = 0L

  internal val flowControlListener: FlowControlListener = builder.flowControlListener

   *
   * <p><b>Note:</b> if mutability is not required, use {@link ImmutableSet#of()} instead. If {@code
   * E} is an {@link Enum} type, use {@link EnumSet#noneOf} instead. Otherwise, strongly consider
   * using a {@code LinkedHashSet} instead, at the cost of increased memory footprint, to get
   * deterministic iteration behavior.
   *

   * explicit {@code @NullableDecl} annotation (see <a
   * href="https://github.com/google/guava/issues/1819">#1819</a>).
   *
   * <p>It is not necessary to consider visibility, return type, or type parameter declarations. The
   * declaration of a method with the same name and formal parameters as {@link Object#equals} that

   *     address has a scope ID that fails validation against the interfaces on the machine (as
   *     required by Java's {@link InetAddress})
   */
  @CanIgnoreReturnValue // TODO(b/219820829): consider removing
  public static InetAddress forString(String ipString) {
    Scope scope = new Scope();
    byte[] addr = ipStringToBytes(ipString, scope);

    // The argument was malformed, i.e. not an IP string literal.