@NullMarked
public abstract class AbstractBiMapTester<K extends @Nullable Object, V extends @Nullable Object>
    extends AbstractMapTester<K, V> {

  @Override
  protected BiMap<K, V> getMap() {
    return (BiMap<K, V>) super.getMap();
  }

  static <K extends @Nullable Object, V extends @Nullable Object> Entry<V, K> reverseEntry(
      Entry<K, V> entry) {
    return mapEntry(entry.getValue(), entry.getKey());
  }

  public void testToString_minimal() {
    assertNotNull("toString() should not return null", getMap().toString());
  }

  @CollectionSize.Require(ZERO)
  @CollectionFeature.Require(absent = NON_STANDARD_TOSTRING)
  public void testToString_size0() {
    assertEquals("emptyMap.toString should return {}", "{}", getMap().toString());
  }

  @CollectionSize.Require(ONE)

    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())) {

  }

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testPut_supportedPresent() {
    assertEquals("put(present, value) should return the old value", v0(), getMap().put(k0(), v3()));
    expectReplacement(entry(k0(), v3()));
  }

  @MapFeature.Require(SUPPORTS_PUT)
  public void testPut_supportedNotPresent() {
    assertNull("put(notPresent, value) should return null", put(e3()));

    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())) {

  }

  @MapFeature.Require(SUPPORTS_PUT)
  public void testPutAll_supportedNothing() {
    getMap().putAll(emptyMap());
    expectUnchanged();
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)
  public void testPutAll_unsupportedNothing() {
    try {
      getMap().putAll(emptyMap());
    } catch (UnsupportedOperationException tolerated) {
    }
    expectUnchanged();
  }

  public void testForEachKnownOrder() {
    List<Entry<K, V>> entries = new ArrayList<>();
    getMap().forEach((k, v) -> entries.add(entry(k, v)));
    assertEquals(getOrderedElements(), entries);
  }

  @CollectionFeature.Require(absent = KNOWN_ORDER)
  public void testForEachUnknownOrder() {
    List<Entry<K, V>> entries = new ArrayList<>();
    getMap().forEach((k, v) -> entries.add(entry(k, v)));

  public void testForEachKnownOrder() {
    List<Entry<K, V>> entries = new ArrayList<>();
    getMap().forEach((k, v) -> entries.add(entry(k, v)));
    assertEquals(getOrderedElements(), entries);
  }

  @CollectionFeature.Require(absent = KNOWN_ORDER)
  public void testForEachUnknownOrder() {
    List<Entry<K, V>> entries = new ArrayList<>();
    getMap().forEach((k, v) -> entries.add(entry(k, v)));

  @CollectionFeature.Require(SERIALIZABLE)
  public void testReserializeMap() {
    Map<K, V> deserialized = SerializableTester.reserialize(getMap());
    new EqualsTester().addEqualityGroup(getMap(), deserialized).testEquals();
  }

public class BiMapInverseTester<K, V> extends AbstractBiMapTester<K, V> {

  public void testInverseSame() {
    assertSame(getMap(), getMap().inverse().inverse());
  }

  @CollectionFeature.Require(SERIALIZABLE)
  public void testInverseSerialization() {
    BiMapPair<K, V> pair = new BiMapPair<>(getMap());
    BiMapPair<K, V> copy = SerializableTester.reserialize(pair);
    assertEquals(pair.forward, copy.forward);