* consistency, and because the return type conveys the immutability guarantee.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */
  @SuppressWarnings({"unchecked"}) // fully variant implementation (never actually produces any Es)
  public static <E> ImmutableSet<E> of() {
    return (ImmutableSet<E>) RegularImmutableSet.EMPTY;
  }

  /**

   * The basic data structure is described in https://en.wikipedia.org/wiki/Open_addressing.
   * The pointer to a key is stored in hashTable[Hashing.smear(key.hashCode()) % table.length],
   * save that if that location is already full, we try the next index, and the next, until we
   * find an empty table position.  Since the table has a power-of-two size, we use
   * & (table.length - 1) instead of % table.length, though.
   */

    return Iterators.addAll(addTo, checkNotNull(elementsToAdd).iterator());
  }

  /**
   * Returns the number of elements in the specified iterable that equal the specified object. This
   * implementation avoids a full iteration when the iterable is a {@link Multiset} or {@link Set}.
   *
   * <p><b>Java 8+ users:</b> In most cases, the {@code Stream} equivalent of this method is {@code

    private ImmutableMap<K, V> build(boolean throwIfDuplicateKeys) {
      if (throwIfDuplicateKeys && duplicateKey != null) {
        throw duplicateKey.exception();
      }
      /*
       * If entries is full, then this implementation may end up using the entries array
       * directly and writing over the entry objects with non-terminal entries, but this is

  "nullness", // TODO(b/147136275): Remove once our checker understands & and |.
})
@GwtCompatible(emulated = true)
@ReflectionSupport(value = ReflectionSupport.Level.FULL)
@ElementTypesAreNonnullByDefault
public abstract class AbstractFuture<V extends @Nullable Object> extends InternalFutureFailureAccess
    implements ListenableFuture<V> {

   * NavigableSet#tailSet(Object, boolean) tailSet()}, and {@link NavigableSet#headSet(Object,
   * boolean) headSet()}) to actually construct the view. Consult these methods for a full
   * description of the returned view's behavior.
   *
   * <p><b>Warning:</b> {@code Range}s always represent a range of values using the values' natural

   * @since 8.0
   */
  public <E extends T> List<E> greatestOf(Iterable<E> iterable, int k) {
    // TODO(kevinb): see if delegation is hurting performance noticeably
    // TODO(kevinb): if we change this implementation, add full unit tests.
    return this.<E>reverse().leastOf(iterable, k);
  }

  /**
   * Returns the {@code k} greatest elements from the given iterator according to this ordering, in

   * NavigableMap#tailMap(Object, boolean) tailMap()}, and {@link NavigableMap#headMap(Object,
   * boolean) headMap()}) to actually construct the view. Consult these methods for a full
   * description of the returned view's behavior.
   *
   * <p><b>Warning:</b> {@code Range}s always represent a range of values using the values' natural

   * Sec-CH-UA-Full-Version}</a> header field name.
   *
   * @deprecated Prefer {@link SEC_CH_UA_FULL_VERSION_LIST}.
   * @since 30.0
   */
  @Deprecated public static final String SEC_CH_UA_FULL_VERSION = "Sec-CH-UA-Full-Version";
  /**
   * The HTTP <a href="https://wicg.github.io/ua-client-hints/#sec-ch-ua-full-version-list">{@code