map.remove("bar");
    assertThat(map.entrySet())
        .containsExactly(immutableEntry("foo", 1), immutableEntry("quux", 3))
        .inOrder();
  }

  public void testInsertionOrderAfterRemoveLast() {
    BiMap<String, Integer> map = HashBiMap.create();
    map.put("foo", 1);
    map.put("bar", 2);
    map.put("quux", 3);

    map.remove("quux");
    assertThat(map.entrySet())

    // TODO: can these be moved to MapInterfaceTest?
    for (Entry<K, V> entry : map.entrySet()) {
      assertEquals(entry.getKey() + "=" + entry.getValue(), entry.toString());
    }

    assertEquals("{" + JOINER.join(map.entrySet()) + "}", map.toString());
    assertEquals("[" + JOINER.join(map.entrySet()) + "]", map.entrySet().toString());
    assertEquals("[" + JOINER.join(map.keySet()) + "]", map.keySet().toString());

    // TODO: can these be moved to MapInterfaceTest?
    for (Entry<K, V> entry : map.entrySet()) {
      assertEquals(entry.getKey() + "=" + entry.getValue(), entry.toString());
    }

    assertEquals("{" + joiner.join(map.entrySet()) + "}", map.toString());
    assertEquals("[" + joiner.join(map.entrySet()) + "]", map.entrySet().toString());
    assertEquals("[" + joiner.join(map.keySet()) + "]", map.keySet().toString());

  /**
   * A sensible definition of {@link #firstEntry()} in terms of {@code entrySet().iterator()}.
   *
   * <p>If you override {@link #entrySet()}, you may wish to override {@link #firstEntry()} to
   * forward to this implementation.
   */
  @CheckForNull
  protected Entry<E> standardFirstEntry() {
    Iterator<Entry<E>> entryIterator = entrySet().iterator();
    if (!entryIterator.hasNext()) {
      return null;
    }

  @LazyInit @CheckForNull private transient Set<Entry<E>> entrySet;

  @Override
  public Set<Entry<E>> entrySet() {
    Set<Entry<E>> result = entrySet;
    return (result == null) ? entrySet = createEntrySet() : result;
  }

  Set<Entry<E>> createEntrySet() {
    @WeakOuter
    class EntrySetImpl extends Multisets.EntrySet<E> {
      @Override
      Multiset<E> multiset() {

          SerializableTester.reserializeAndAssert(asMap);
          SerializableTester.reserializeAndAssert(descendingMap);
          assertEquals(
              ImmutableList.copyOf(asMap.entrySet()).reverse(),
              ImmutableList.copyOf(descendingMap.entrySet()));

          for (Range<Integer> query : RANGES) {
            assertEquals(expectedAsMap.get(query), asMap.get(query));
          }
        }
      }
    }
  }

    for (Entry<K, V> entry : getMap().entrySet()) {
      assertThrows(NullPointerException.class, () -> entry.setValue(null));
      expectUnchanged();
    }
  }

  @MapFeature.Require({SUPPORTS_PUT, ALLOWS_NULL_VALUES})
  @CollectionSize.Require(absent = ZERO)
  public void testSetValueNullSupported() {
    for (Entry<K, V> entry : getMap().entrySet()) {
      if (entry.getKey().equals(k0())) {
        entry.setValue(null);

    for (Entry<K, V> entry : map.entrySet()) {
      assertEquals(entry.getKey() + "=" + entry.getValue(), entry.toString());
      assertEquals(entry.getKey(), bimap.inverse().get(entry.getValue()));
    }

    assertEquals("{" + JOINER.join(map.entrySet()) + "}", map.toString());
    assertEquals("[" + JOINER.join(map.entrySet()) + "]", map.entrySet().toString());

      return standardToString();
    }
  }

  @LazyInit @CheckForNull private transient Set<Entry<K, V>> entrySet;

  @Override
  public Set<Entry<K, V>> entrySet() {
    Set<Entry<K, V>> result = entrySet;
    return (result == null) ? entrySet = new EntrySet() : result;
  }

  class BiMapEntry extends ForwardingMapEntry<K, V> {
    private final Entry<K, V> delegate;

   */
  static <E extends @Nullable Object> void writeMultiset(
      Multiset<E> multiset, ObjectOutputStream stream) throws IOException {
    int entryCount = multiset.entrySet().size();
    stream.writeInt(entryCount);
    for (Multiset.Entry<E> entry : multiset.entrySet()) {
      stream.writeObject(entry.getElement());
      stream.writeInt(entry.getCount());
    }
  }

  /**