* multiset1}, with repeated occurrences of the same element appearing consecutively.
   *
   * <p>Results are undefined if {@code multiset1} and {@code multiset2} are based on different
   * equivalence relations (as {@code HashMultiset} and {@code TreeMultiset} are).
   *
   * @since 14.0
   */
  public static <E extends @Nullable Object> Multiset<E> union(

    // initial capacity / concurrency level
    assertEquals(16 / map.segments.length, map.segments[0].table.length());
  }

  public void testSetKeyEquivalence() {
    Equivalence<Object> testEquivalence =
        new Equivalence<Object>() {
          @Override
          protected boolean doEquivalent(Object a, Object b) {
            return false;
          }

          @Override

    // initial capacity / concurrency level
    assertEquals(16 / map.segments.length, map.segments[0].table.length());
  }

  public void testSetKeyEquivalence() {
    Equivalence<Object> testEquivalence =
        new Equivalence<Object>() {
          @Override
          protected boolean doEquivalent(Object a, Object b) {
            return false;
          }

          @Override

 * by supplied comparators. In all cases, this implementation uses {@link Comparable#compareTo} or
 * {@link Comparator#compare} instead of {@link Object#equals} to determine equivalence of
 * instances.
 *
 * <p><b>Warning:</b> The comparators or comparables used must be <i>consistent with equals</i> as
 * explained by the {@link Comparable} class specification. Otherwise, the resulting multiset will

 * additional documentation, including:
 *
 * <ul>
 *   <li><a
 *       href="https://github.com/google/guava/wiki/GraphsExplained#equals-hashcode-and-graph-equivalence">
 *       {@code equals()}, {@code hashCode()}, and graph equivalence</a>
 *   <li><a href="https://github.com/google/guava/wiki/GraphsExplained#synchronization">
 *       Synchronization policy</a>

    assertFalse(map.expiresAfterWrite());
    assertFalse(map.expiresAfterAccess());
    assertFalse(map.refreshes());
  }

  public void testSetKeyEquivalence() {
    Equivalence<Object> testEquivalence =
        new Equivalence<Object>() {
          @Override
          protected boolean doEquivalent(Object a, Object b) {
            return false;
          }

          @Override

    assertFalse(map.expiresAfterWrite());
    assertFalse(map.expiresAfterAccess());
    assertFalse(map.refreshes());
  }

  public void testSetKeyEquivalence() {
    Equivalence<Object> testEquivalence =
        new Equivalence<Object>() {
          @Override
          protected boolean doEquivalent(Object a, Object b) {
            return false;
          }

          @Override

    assertThat(graph.edgeValueOrDefault(1, 2, null)).isNull();
    assertThat(graph.edgeValueOrDefault(2, 1, null)).isEqualTo("valueC");
  }

  @Test
  public void equivalence_considersEdgeValue() {
    graph = ValueGraphBuilder.undirected().build();
    graph.putEdgeValue(1, 2, "valueA");

    MutableValueGraph<Integer, String> otherGraph = ValueGraphBuilder.undirected().build();

    assertThat(graph.edgeValue(1, 2).orElse(null)).isNull();
    assertThat(graph.edgeValue(2, 1).get()).isEqualTo("valueC");
  }

  @Test
  public void equivalence_considersEdgeValue() {
    graph = ValueGraphBuilder.undirected().build();
    graph.putEdgeValue(1, 2, "valueA");

    MutableValueGraph<Integer, String> otherGraph = ValueGraphBuilder.undirected().build();

   * given object is also a multiset and contains equal elements with equal counts, regardless of
   * order.
   */
  @Override
  // TODO(kevinb): caveats about equivalence-relation?
  boolean equals(@CheckForNull Object object);

  /**
   * Returns the hash code for this multiset. This is defined as the sum of
   *
   * <pre>{@code