AvlNode<E> newRoot = new AvlNode<>(element, occurrences);
      successor(header, newRoot, header);
      rootReference.checkAndSet(root, newRoot);
      return 0;
    }
    int[] result = new int[1]; // used as a mutable int reference to hold result
    AvlNode<E> newRoot = root.add(comparator(), element, occurrences, result);
    rootReference.checkAndSet(root, newRoot);
    return result[0];
  }

  @CanIgnoreReturnValue

 *
 * <p>This class maintains a map of nodes to {@link GraphConnections}.
 *
 * <p>Collection-returning accessors return unmodifiable views: the view returned will reflect
 * changes to the graph (if the graph is mutable) but may not be modified by the user.
 *
 * <p>The time complexity of all collection-returning accessors is O(1), since views are returned.
 *
 * @author James Sexton
 * @author Joshua O'Madadhain
 * @author Omar Darwish

import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Set;
import org.jspecify.annotations.NonNull;
import org.jspecify.annotations.Nullable;

/**
 * A mutable class-to-instance map backed by an arbitrary user-provided map. See also {@link
 * ImmutableClassToInstanceMap}.
 *
 * <p>See the Guava User Guide article on <a href=

  /**
   * Reduces the memory used by this {@code ArrayListMultimap}, if feasible.
   *
   * @deprecated For a {@link ListMultimap} that automatically trims to size, use {@link
   *     ImmutableListMultimap}. If you need a mutable collection, remove the {@code trimToSize}
   *     call, or switch to a {@code HashMap<K, ArrayList<V>>}.
   */
  @Deprecated
  public void trimToSize() {
    for (Collection<V> collection : backingMap().values()) {

  }

  private static <T extends @Nullable Object> List<T> shuffledCopy(List<T> in, Random random) {
    List<T> mutable = new ArrayList<>(in);
    List<T> out = new ArrayList<>();
    while (!mutable.isEmpty()) {
      out.add(mutable.remove(random.nextInt(mutable.size())));
    }
    return out;
  }

  }

  private static <T extends @Nullable Object> List<T> shuffledCopy(List<T> in, Random random) {
    List<T> mutable = new ArrayList<>(in);
    List<T> out = new ArrayList<>();
    while (!mutable.isEmpty()) {
      out.add(mutable.remove(random.nextInt(mutable.size())));
    }
    return out;
  }

  private lateinit var serverIpv6: MockWebServer

  private val eventRecorder = EventRecorder()
  private lateinit var client: OkHttpClient
  private lateinit var url: HttpUrl

  /**
   * This is mutable and order matters. By default, it contains [IPv4, IPv6]. Tests may manipulate
   * it to prefer IPv6.
   */
  private var dnsResults = listOf<InetAddress>()

  @BeforeEach
  internal fun setUp() {

  /** Creates an empty {@code CompactLinkedHashSet} instance. */
  public static <E extends @Nullable Object> CompactLinkedHashSet<E> create() {
    return new CompactLinkedHashSet<>();
  }

  /**
   * Creates a <i>mutable</i> {@code CompactLinkedHashSet} instance containing the elements of the
   * given collection in the order returned by the collection's iterator.
   *
   * @param collection the elements that the set should contain

  /** Creates an empty {@code CompactLinkedHashSet} instance. */
  public static <E extends @Nullable Object> CompactLinkedHashSet<E> create() {
    return new CompactLinkedHashSet<>();
  }

  /**
   * Creates a <i>mutable</i> {@code CompactLinkedHashSet} instance containing the elements of the
   * given collection in the order returned by the collection's iterator.
   *
   * @param collection the elements that the set should contain

        orderedNodeConnections,
        /* predecessorCount= */ 0,
        /* successorCount= */ 0);
  }

  static <N, V> DirectedGraphConnections<N, V> ofImmutable(
      N thisNode, Iterable<EndpointPair<N>> incidentEdges, Function<N, V> successorNodeToValueFn) {
    checkNotNull(thisNode);
    checkNotNull(successorNodeToValueFn);