*
     * @param <K> the key type of {@link IdentityHashMap}
     * @param <V> the value type of {@link IdentityHashMap}
     * @return a new instance of {@link IdentityHashMap}
     * @see IdentityHashMap#IdentityHashMap()
     */
    public static <K, V> IdentityHashMap<K, V> newIdentityHashMap() {
        return new IdentityHashMap<>();
    }

    /**

import com.google.common.collect.ImmutableMapEntry.NonTerminalImmutableMapEntry;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.io.Serializable;
import java.util.IdentityHashMap;
import java.util.function.BiConsumer;
import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@link ImmutableMap} used for 0 entries and for 2+ entries. Additional

   * an element in the set. For example, {@code contains} returns {@code false} when passed an
   * object that equals a set member, but isn't the same instance. This behavior is similar to the
   * way {@code IdentityHashMap} handles key lookups.
   *
   * @since 8.0
   */
  public static <E extends @Nullable Object> Set<E> newIdentityHashSet() {
    return Collections.newSetFromMap(Maps.newIdentityHashMap());
  }

  /**

            CollectionFeature.SERIALIZABLE,
            CollectionSize.ANY)
        .suppressing(suppressForConcurrentSkipListMap())
        .createTestSuite();
  }

  // TODO: IdentityHashMap, AbstractMap

  private static Map<String, String> toHashMap(Entry<String, String>[] entries) {
    return populate(new HashMap<String, String>(), entries);
  }

/**
 * A general-purpose bimap implementation using any two backing {@code Map} instances.
 *
 * <p>Note that this class contains {@code equals()} calls that keep it from supporting {@code
 * IdentityHashMap} backing maps.
 *
 * @author Kevin Bourrillion
 * @author Mike Bostock
 */
@GwtCompatible
abstract class AbstractBiMap<K extends @Nullable Object, V extends @Nullable Object>

   * an element in the set. For example, {@code contains} returns {@code false} when passed an
   * object that equals a set member, but isn't the same instance. This behavior is similar to the
   * way {@code IdentityHashMap} handles key lookups.
   *
   * @since 8.0
   */
  public static <E extends @Nullable Object> Set<E> newIdentityHashSet() {
    return Collections.newSetFromMap(Maps.newIdentityHashMap());
  }

  /**

    @GuardedBy("monitor")
    final Multiset<State> states = servicesByState.keys();

    @GuardedBy("monitor")
    final IdentityHashMap<Service, Stopwatch> startupTimers = new IdentityHashMap<>();

    /**
     * These two booleans are used to mark the state as ready to start.
     *
     * <p>{@link #ready}: is set by {@link #markReady} to indicate that all listeners have been

            CollectionFeature.SERIALIZABLE,
            CollectionSize.ANY)
        .suppressing(suppressForConcurrentSkipListMap())
        .createTestSuite();
  }

  // TODO: IdentityHashMap, AbstractMap

  private static Map<String, String> toHashMap(Entry<String, String>[] entries) {
    return populate(new HashMap<String, String>(), entries);
  }

/**
 * A general-purpose bimap implementation using any two backing {@code Map} instances.
 *
 * <p>Note that this class contains {@code equals()} calls that keep it from supporting {@code
 * IdentityHashMap} backing maps.
 *
 * @author Kevin Bourrillion
 * @author Mike Bostock
 */
@GwtCompatible
abstract class AbstractBiMap<K extends @Nullable Object, V extends @Nullable Object>

    HashMap<Object, Object> map = Maps.<Object, Object>newLinkedHashMap(original);
    assertEquals(original, map);
  }

  // Intentionally using IdentityHashMap to test creation.
  @SuppressWarnings("IdentityHashMapBoxing")
  public void testIdentityHashMap() {
    IdentityHashMap<Integer, Integer> map = Maps.newIdentityHashMap();
    assertEquals(emptyMap(), map);
  }

  public void testConcurrentMap() {