v1 ^= v0;
        v3 ^= v2;
        v0 = Long.rotateLeft(v0, 32);
        v2 += v1;
        v0 += v3;
        v1 = Long.rotateLeft(v1, 17);
        v3 = Long.rotateLeft(v3, 21);
        v1 ^= v2;
        v3 ^= v0;
        v2 = Long.rotateLeft(v2, 32);
      }
    }
  }

  private static final long serialVersionUID = 0L;

      K k1, V v1, K k2, V v2) {
    return new Builder<K, V>(Ordering.natural()).put(k1, v1).put(k2, v2).build();
  }

  public static <K extends Comparable<? super K>, V> ImmutableSortedMap<K, V> of(
      K k1, V v1, K k2, V v2, K k3, V v3) {
    return new Builder<K, V>(Ordering.natural()).put(k1, v1).put(k2, v2).put(k3, v3).build();
  }

  public static <K, V> ImmutableBiMap<K, V> of(K k1, V v1, K k2, V v2) {
    return RegularImmutableBiMap.fromEntries(entryOf(k1, v1), entryOf(k2, v2));
  }

  /**
   * Returns an immutable map containing the given entries, in order.
   *
   * @throws IllegalArgumentException if duplicate keys or values are added
   */
  public static <K, V> ImmutableBiMap<K, V> of(K k1, V v1, K k2, V v2, K k3, V v3) {

  public void testReplaceValuesWithNullKey() {
    List<V> values = Arrays.asList(v0(), v2(), v3());
    multimap().replaceValues(null, values);
    assertGet(null, values);
  }

  @MapFeature.Require({SUPPORTS_PUT, SUPPORTS_REMOVE})
  public void testReplaceEmptyValues() {
    int size = multimap().size();
    List<V> values = Arrays.asList(v0(), v2(), v3());
    multimap().replaceValues(k3(), values);
    assertGet(k3(), values);

  public void testRemoveAllMultipleValues() {
    resetContainer(
        Helpers.mapEntry(k0(), v0()), Helpers.mapEntry(k0(), v1()), Helpers.mapEntry(k0(), v2()));

    assertContentsAnyOrder(multimap().removeAll(k0()), v0(), v1(), v2());
    assertEmpty(multimap());
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require({SUPPORTS_REMOVE, ALLOWS_NULL_KEYS})

    int size = getNumElements();

    List<V> values = Helpers.copyToList(multimap().get(k0()));

    assertTrue(multimap().put(k0(), v1()));
    assertTrue(multimap().put(k0(), v2()));

    values.add(v1());
    values.add(v2());

    assertGet(k0(), values);
    assertEquals(size + 2, multimap().size());
  }

  @MapFeature.Require({SUPPORTS_PUT, ALLOWS_NULL_VALUES})

  public static <K, V> ImmutableBiMap<K, V> of(K k1, V v1, K k2, V v2) {
    return new RegularImmutableBiMap<K, V>(ImmutableMap.of(k1, v1, k2, v2));
  }

  public static <K, V> ImmutableBiMap<K, V> of(K k1, V v1, K k2, V v2, K k3, V v3) {
    return new RegularImmutableBiMap<K, V>(ImmutableMap.of(k1, v1, k2, v2, k3, v3));
  }

  public static <K, V> ImmutableBiMap<K, V> of(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4) {

    assertFalse(multimap().isEmpty());
  }

  @CollectionSize.Require(SEVERAL)
  public void testSizeMultipleValues() {
    resetContainer(mapEntry(k0(), v0()), mapEntry(k0(), v1()), mapEntry(k0(), v2()));

    assertEquals(3, multimap().size());
    assertEquals(3, multimap().entries().size());
    assertEquals(3, multimap().keys().size());

    assertEquals(1, multimap().keySet().size());

    assertFalse(multimap().isEmpty());
  }

  @CollectionSize.Require(SEVERAL)
  public void testSizeMultipleValues() {
    resetContainer(mapEntry(k0(), v0()), mapEntry(k0(), v1()), mapEntry(k0(), v2()));

    assertEquals(3, multimap().size());
    assertEquals(3, multimap().entries().size());
    assertEquals(3, multimap().keys().size());

    assertEquals(1, multimap().keySet().size());

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(SEVERAL)
  public void testForcePutKeyAndValuePresent() {
    getMap().forcePut(k0(), v1());
    expectContents(Helpers.mapEntry(k0(), v1()), Helpers.mapEntry(k2(), v2()));
    assertEquals(2, getMap().size());
    assertFalse(getMap().containsKey(k1()));
    assertFalse(getMap().containsValue(v0()));
  }

  @MapFeature.Require({SUPPORTS_PUT, ALLOWS_NULL_KEYS})