@CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(ALLOWS_NULL_KEYS)
  public void testContainsEntryWithNullKeyPresent() {
    initMapWithNullKey();
    assertTrue(getMap().entrySet().contains(mapEntry(null, getValueForNullKey())));
  }

  @MapFeature.Require(ALLOWS_NULL_VALUE_QUERIES)
  public void testContainsEntryWithNullValueAbsent() {
    assertFalse(getMap().entrySet().contains(mapEntry(k0(), null)));
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(ALLOWS_NULL_KEYS)
  public void testContainsEntryWithNullKeyPresent() {
    initMapWithNullKey();
    assertTrue(getMap().entrySet().contains(mapEntry(null, getValueForNullKey())));
  }

  @MapFeature.Require(ALLOWS_NULL_VALUE_QUERIES)
  public void testContainsEntryWithNullValueAbsent() {
    assertFalse(getMap().entrySet().contains(mapEntry(k0(), null)));
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(ALLOWS_NULL_KEYS)
  public void testAsMapGetNullKeyPresent() {
    initMultimapWithNullKey();
    assertContentsAnyOrder(multimap().asMap().get(null), getValueForNullKey());
  }

  @MapFeature.Require(ALLOWS_NULL_KEY_QUERIES)
  public void testAsMapGetNullKeyAbsent() {
    assertNull(multimap().asMap().get(null));
  }

  @MapFeature.Require(absent = ALLOWS_NULL_KEY_QUERIES)

  public void testPut_nullKeySupportedPresent() {
    Entry<K, V> newEntry = entry(null, v3());
    initMapWithNullKey();
    assertEquals(
        "put(present, value) should return the associated value",
        getValueForNullKey(),
        put(newEntry));

    Entry<K, V>[] expected = createArrayWithNullKey();
    expected[getNullLocation()] = newEntry;
    expectContents(expected);
  }

    int nullKeyLocation = getNullLocation();
    Entry<K, V> oldEntry = array[nullKeyLocation];
    array[nullKeyLocation] = entry(null, oldEntry.getValue());
    return array;
  }

  protected V getValueForNullKey() {
    return getEntryNullReplaces().getValue();
  }

  protected K getKeyForNullValue() {
    return getEntryNullReplaces().getKey();
  }

  private Entry<K, V> getEntryNullReplaces() {