import java.lang.ref.ReferenceQueue;
import org.jspecify.annotations.Nullable;

/**
 * Phantom reference with a {@code finalizeReferent()} method which a background thread invokes
 * after the garbage collector reclaims the referent. This is a simpler alternative to using a
 * {@link ReferenceQueue}.
 *
 * <p>Unlike a normal phantom reference, this reference will be cleared automatically.
 *
 * @author Bob Lee
 * @since 2.0

import java.lang.ref.WeakReference;
import org.jspecify.annotations.Nullable;

/**
 * Weak reference with a {@code finalizeReferent()} method which a background thread invokes after
 * the garbage collector reclaims the referent. This is a simpler alternative to using a {@link
 * ReferenceQueue}.
 *
 * @author Bob Lee
 * @since 2.0
 */
@J2ktIncompatible
@GwtIncompatible

import java.util.function.Function;
import java.util.stream.Collector;
import org.jspecify.annotations.Nullable;

/**
 * GWT emulation of {@link com.google.common.collect.ImmutableBiMap}.
 *
 * @author Hayward Chan
 */
public abstract class ImmutableBiMap<K, V> extends ForwardingImmutableMap<K, V>
    implements BiMap<K, V> {
  public static <T extends @Nullable Object, K, V>
      Collector<T, ?, ImmutableBiMap<K, V>> toImmutableBiMap(

import java.util.Iterator;
import java.util.Map;
import java.util.SortedMap;
import java.util.TreeMap;
import java.util.function.BinaryOperator;
import java.util.function.Function;
import java.util.stream.Collector;
import java.util.stream.Collectors;
import org.jspecify.annotations.Nullable;

/**
 * GWT emulated version of {@link com.google.common.collect.ImmutableSortedMap}. It's a thin wrapper
 * around a {@link java.util.TreeMap}.
 *

   * from the {@code Collector} returned by {@link Collectors#toMap(Function, Function)}, which
   * throws an {@code IllegalStateException}.)
   *
   * @since 33.2.0 (available since 21.0 in guava-jre)
   */
  @IgnoreJRERequirement // Users will use this only if they're already using streams.
  public static <T extends @Nullable Object, K, V>
      Collector<T, ?, ImmutableSortedMap<K, V>> toImmutableSortedMap(

   */
  public static Collector<Number, StatsAccumulator, Stats> toStats() {
    return Collector.of(
        StatsAccumulator::new,
        (a, x) -> a.add(x.doubleValue()),
        (l, r) -> {
          l.addAll(r);
          return l;
        },
        StatsAccumulator::snapshot,
        Collector.Characteristics.UNORDERED);
  }

  /** Returns the number of values. */

    implements List<E>, RandomAccess {

  /**
   * Returns a {@code Collector} that accumulates the input elements into a new {@code
   * ImmutableList}, in encounter order.
   *
   * @since 33.2.0 (available since 21.0 in guava-jre)
   */
  @IgnoreJRERequirement // Users will use this only if they're already using streams.
  public static <E> Collector<E, ?, ImmutableList<E>> toImmutableList() {

import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.RandomAccess;
import java.util.stream.Collector;
import jsinterop.annotations.JsMethod;
import org.jspecify.annotations.Nullable;

/**
 * GWT emulated version of {@link com.google.common.collect.ImmutableList}. TODO(cpovirk): more doc
 *
 * @author Hayward Chan

import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.NoSuchElementException;
import java.util.Set;
import java.util.stream.Collector;
import org.jspecify.annotations.Nullable;

/**
 * A {@link RangeSet} whose contents will never change, with many other important properties
 * detailed at {@link ImmutableCollection}.
 *
 * @author Louis Wasserman

   * {@code stream.map(function).collect(Collectors.toCollection(supplier))}.
   *
   * <p>To collect to an {@link ImmutableMultiset}, use {@link
   * ImmutableMultiset#toImmutableMultiset}.
   *
   * @since 22.0
   */
  public static <T extends @Nullable Object, E extends @Nullable Object, M extends Multiset<E>>
      Collector<T, ?, M> toMultiset(
          Function<? super T, E> elementFunction,