/**
   * {@inheritDoc}
   *
   * <p>The iterator generated by the returned collection traverses the values in the order they
   * were added to the multimap. Because the values may have duplicates and follow the insertion
   * ordering, this method returns a {@link List}, instead of the {@link Collection} specified in
   * the {@link ListMultimap} interface.
   */
  @Override
  public List<V> values() {

   */
  public long approximateElementCount() {
    long bitSize = bits.bitSize();
    long bitCount = bits.bitCount();

    /*
     * Each insertion is expected to reduce the # of clear bits by a factor of
     * `numHashFunctions/bitSize`. So, after n insertions, expected bitCount is `bitSize * (1 - (1 -
     * numHashFunctions/bitSize)^n)`. Solving that for n, and approximating `ln x` as `x - 1` when x

import java.util.Map;
import java.util.Set;
import java.util.Spliterator;
import java.util.Spliterators;
import org.jspecify.annotations.Nullable;

/**
 * CompactLinkedHashMap is an implementation of a Map with insertion or LRU iteration order,
 * maintained with a doubly linked list through the entries. All optional operations (put and
 * remove) are supported. Null keys and values are supported.
 *

  // type V, PRED (representing predecessor), or an instance of type V (representing successor).
  private final Map<N, Object> adjacentNodeValues;

  /**
   * All node connections in this graph, in edge insertion order.
   *
   * <p>Note: This field and {@link #adjacentNodeValues} cannot be combined into a single
   * LinkedHashMap because one target node may be mapped to both a predecessor and a successor. A

 * {@code ObjectCountHashMap} minimizes object allocation and reduces memory footprint.
 *
 * <p>In the absence of element deletions, this will iterate over elements in insertion order.
 */
@GwtCompatible
@NullMarked
class ObjectCountHashMap<K extends @Nullable Object> {

  /** Creates an empty {@code ObjectCountHashMap} instance. */

 * OutOfMemoryError}). This class does not permit {@code null} elements. A priority queue relying on
 * {@linkplain Comparable natural ordering} also does not permit insertion of non-comparable objects
 * (doing so results in {@code ClassCastException}).
 *
 * <p>This class and its iterator implement all of the optional methods of the {@link

      // to be sorted based on the top of each iterator, with insertion order as tiebreaker
      Comparator<IndexedIterator<T>> heapComparator =
          (o1, o2) ->
              ComparisonChain.start()
                  .compare(o1.iterator.peek(), o2.iterator.peek(), itemComparator)
                  // When elements are equal, use insertion order to maintain stability
                  .compare(o1.index, o2.index)

 * terms</a>):
 *
 * <ul>
 *   <li>directed graphs
 *   <li>undirected graphs
 *   <li>graphs that do/don't allow self-loops
 *   <li>graphs whose nodes/edges are insertion-ordered, sorted, or unordered
 *   <li>graphs whose edges have associated values
 * </ul>
 *
 * <p>{@code ValueGraph}, as a subtype of {@code Graph}, explicitly does not support parallel edges,

 * terms</a>):
 *
 * <ul>
 *   <li>directed graphs
 *   <li>undirected graphs
 *   <li>graphs that do/don't allow self-loops
 *   <li>graphs whose nodes/edges are insertion-ordered, sorted, or unordered
 * </ul>
 *
 * <p>{@code Graph} explicitly does not support parallel edges, and forbids implementations or
 * extensions with parallel edges. If you need parallel edges, use {@link Network}.
 *

 * terms</a>):
 *
 * <ul>
 *   <li>directed graphs
 *   <li>undirected graphs
 *   <li>graphs that do/don't allow self-loops
 *   <li>graphs whose nodes/edges are insertion-ordered, sorted, or unordered
 * </ul>
 *
 * <p>{@code Graph} explicitly does not support parallel edges, and forbids implementations or
 * extensions with parallel edges. If you need parallel edges, use {@link Network}.
 *