@CollectionSize.Require(ZERO)
  public void testIsEmpty_yes() {
    assertTrue("isEmpty() should return true", getMap().isEmpty());
  }

  @CollectionSize.Require(absent = ZERO)
  public void testIsEmpty_no() {
    assertFalse("isEmpty() should return false", getMap().isEmpty());
  }

  @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);

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);

    for (Entry<K, V> entry : getSampleEntries()) {
      expectedHashCode += hash(entry);
    }
    assertEquals(
        "A Map's hashCode() should be the sum of those of its entries.",
        expectedHashCode,
        getMap().hashCode());
  }

  @CollectionSize.Require(absent = CollectionSize.ZERO)
  @MapFeature.Require(ALLOWS_NULL_KEYS)
  public void testHashCode_containingNullKey() {
    Entry<K, V> entryWithNull = entry(null, v3());

  @CollectionSize.Require(ZERO)
  public void testIsEmpty_yes() {
    assertTrue("isEmpty() should return true", getMap().isEmpty());
  }

  @CollectionSize.Require(absent = ZERO)
  public void testIsEmpty_no() {
    assertFalse("isEmpty() should return false", getMap().isEmpty());
  }

@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class MapSizeTester<K, V> extends AbstractMapTester<K, V> {
  public void testSize() {
    assertEquals("size():", getNumElements(), getMap().size());
  }

    for (Entry<K, V> entry : getSampleEntries()) {
      expectedHashCode += hash(entry);
    }
    assertEquals(
        "A Map's hashCode() should be the sum of those of its entries.",
        expectedHashCode,
        getMap().hashCode());
  }

  @CollectionSize.Require(absent = CollectionSize.ZERO)
  @MapFeature.Require(ALLOWS_NULL_KEYS)
  public void testHashCode_containingNullKey() {
    Entry<K, V> entryWithNull = entry(null, v3());

  private Entry<K, V> a;
  private Entry<K, V> b;
  private Entry<K, V> c;

  @Override
  public void setUp() throws Exception {
    super.setUp();
    navigableMap = (NavigableMap<K, V>) getMap();
    entries =
        copyToList(
            getSubjectGenerator()
                .getSampleElements(getSubjectGenerator().getCollectionSize().getNumElements()));

@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class MapSizeTester<K, V> extends AbstractMapTester<K, V> {
  public void testSize() {
    assertEquals("size():", getNumElements(), getMap().size());
  }