@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

   * 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.<E, Boolean>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);
  }

            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(emulated = true)
@ElementTypesAreNonnullByDefault

   * syntax</a>.
   *
   * @return a new, empty {@code IdentityHashMap}
   */
  public static <K extends @Nullable Object, V extends @Nullable Object>
      IdentityHashMap<K, V> newIdentityHashMap() {
    return new IdentityHashMap<>();
  }

  /**
   * Computes the difference between two maps. This difference is an immutable snapshot of the state

   * syntax</a>.
   *
   * @return a new, empty {@code IdentityHashMap}
   */
  public static <K extends @Nullable Object, V extends @Nullable Object>
      IdentityHashMap<K, V> newIdentityHashMap() {
    return new IdentityHashMap<>();
  }

  /**
   * Computes the difference between two maps. This difference is an immutable snapshot of the state

import com.google.j2objc.annotations.J2ObjCIncompatible;
import java.lang.ref.SoftReference;
import java.lang.ref.WeakReference;
import java.time.Duration;
import java.util.ConcurrentModificationException;
import java.util.IdentityHashMap;
import java.util.Map;
import java.util.concurrent.TimeUnit;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.annotation.CheckForNull;

/**

    return state.compareAndSet(oldState, newState);
  }

  // TODO(dpb): Should we use a pair of ArrayLists instead of an IdentityHashMap?
  private static final class CloseableList extends IdentityHashMap<AutoCloseable, Executor>
      implements Closeable {
    private final DeferredCloser closer = new DeferredCloser(this);
    private volatile boolean closed;

import com.google.j2objc.annotations.J2ObjCIncompatible;
import java.lang.ref.SoftReference;
import java.lang.ref.WeakReference;
import java.time.Duration;
import java.util.ConcurrentModificationException;
import java.util.IdentityHashMap;
import java.util.Map;
import java.util.concurrent.TimeUnit;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.annotation.CheckForNull;

/**