} catch (ClassCastException acceptable) {
      // allowed by the spec
    }
  }

  @MapFeature.Require(ALLOWS_NULL_KEY_QUERIES)
  public void testContainsEntryWithNullKeyAbsent() {
    assertFalse(getMap().entrySet().contains(Helpers.mapEntry(null, v0())));
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(ALLOWS_NULL_KEYS)
  public void testContainsEntryWithNullKeyPresent() {
    initMapWithNullKey();

    } catch (ClassCastException acceptable) {
      // allowed by the spec
    }
  }

  @MapFeature.Require(ALLOWS_NULL_KEY_QUERIES)
  public void testContainsEntryWithNullKeyAbsent() {
    assertFalse(getMap().entrySet().contains(Helpers.mapEntry(null, v0())));
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(ALLOWS_NULL_KEYS)
  public void testContainsEntryWithNullKeyPresent() {
    initMapWithNullKey();

#
# In go 1.15, the tidy main module must require a (because it is direct),
# c (because it is a missing test dependency of an imported package),
# and d (because it is a missing transitive test dependency).
#
# In go 1.16, the tidy main module can omit d because it is no longer
# included in "all".
#
# In go 1.17, the main module must explicitly require b
# (because it is transitively imported by the main module).

  }

  @CollectionSize.Require(absent = ZERO)
  @CollectionFeature.Require(absent = NON_STANDARD_TOSTRING)
  @MapFeature.Require(ALLOWS_NULL_KEYS)
  public void testToStringWithNullKey() {
    initMultimapWithNullKey();
    testToStringMatchesAsMap();
  }

  @CollectionSize.Require(absent = ZERO)
  @CollectionFeature.Require(absent = NON_STANDARD_TOSTRING)
  @MapFeature.Require(ALLOWS_NULL_VALUES)

  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testRemoveAllPropagatesToMultimap() {
    assertTrue(multimap().entries().removeAll(Collections.singleton(Helpers.mapEntry(k0(), v0()))));
    expectMissing(Helpers.mapEntry(k0(), v0()));
    assertEquals(getNumElements() - 1, multimap().size());
    assertFalse(multimap().containsEntry(k0(), v0()));
  }

  @CollectionSize.Require(absent = ZERO)

    }
    assertEquals(expectedSize, size2);
  }

  @CollectionSize.Require(ZERO)
  public void testIsEmptyYes() {
    assertTrue(multimap().isEmpty());
  }

  @CollectionSize.Require(absent = ZERO)
  public void testIsEmptyNo() {
    assertFalse(multimap().isEmpty());
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(ALLOWS_NULL_KEYS)
  public void testSizeNullKey() {
    initMultimapWithNullKey();

public class CollectionAddAllTester<E extends @Nullable Object>
    extends AbstractCollectionTester<E> {
  @CollectionFeature.Require(SUPPORTS_ADD)
  public void testAddAll_supportedNothing() {
    assertFalse("addAll(nothing) should return false", collection.addAll(emptyCollection()));
    expectUnchanged();
  }

  @CollectionFeature.Require(absent = SUPPORTS_ADD)
  public void testAddAll_unsupportedNothing() {
    try {
      assertFalse(

public class MultimapRemoveEntryTester<K, V> extends AbstractMultimapTester<K, V, Multimap<K, V>> {
  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testRemoveAbsent() {
    assertFalse(multimap().remove(k0(), v1()));
    expectUnchanged();
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testRemovePresent() {
    assertTrue(multimap().remove(k0(), v0()));

public class MultimapRemoveEntryTester<K, V> extends AbstractMultimapTester<K, V, Multimap<K, V>> {
  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testRemoveAbsent() {
    assertFalse(multimap().remove(k0(), v1()));
    expectUnchanged();
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testRemovePresent() {
    assertTrue(multimap().remove(k0(), v0()));

    runRemoveTest(0);
  }

  @ListFeature.Require(SUPPORTS_REMOVE_WITH_INDEX)
  @CollectionSize.Require(absent = {ZERO, ONE})
  public void testRemoveAtIndex_middle() {
    runRemoveTest(getNumElements() / 2);
  }

  @CollectionFeature.Require(FAILS_FAST_ON_CONCURRENT_MODIFICATION)
  @ListFeature.Require(SUPPORTS_REMOVE_WITH_INDEX)
  @CollectionSize.Require(absent = ZERO)
  public void testRemoveAtIndexConcurrentWithIteration() {