expectUnchanged();
  }

  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
  @CollectionSize.Require(ZERO)
  public void testRetainAll_emptyPreviouslyEmptyUnsupported() {
    expectReturnsFalseOrThrows(empty);
    expectUnchanged();
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = ZERO)
  public void testRetainAll_emptyPreviouslyNonEmpty() {

  }

  @CollectionFeature.Require(absent = SUPPORTS_ADD)
  @CollectionSize.Require(absent = ZERO)
  public void testAddAll_unsupportedSomePresent() {
    try {
      collection.addAll(MinimalCollection.of(e3(), e0()));
      fail("addAll(somePresent) should throw");
    } catch (UnsupportedOperationException expected) {
    }
    expectUnchanged();
  }

public class MapComputeTester<K, V> extends AbstractMapTester<K, V> {
  @MapFeature.Require({SUPPORTS_PUT, SUPPORTS_REMOVE})
  public void testCompute_absentToPresent() {
    assertEquals(
        "Map.compute(absent, functionReturningValue) should return value",
        v3(),
        getMap()
            .compute(
                k3(),
                (k, v) -> {
                  assertEquals(k3(), k);

  public void testAbsent() {
    assertEquals(
        "Map.merge(absent, value, function) should return value",
        v3(),
        getMap()
            .merge(
                k3(),
                v3(),
                (oldV, newV) -> {
                  throw new AssertionFailedError(
                      "Should not call merge function if key was absent");
                }));
    expectAdded(e3());
  }

  public void testRemove_occurrences_absent() {
    int distinct = getMultiset().elementSet().size();
    assertEquals("multiset.remove(absent, 0) didn't return 0", 0, getMultiset().remove(e3(), 2));
    assertEquals(distinct, getMultiset().elementSet().size());
  }

  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
  public void testRemove_occurrences_unsupported_absent() {

  @CollectionSize.Require(absent = ZERO)
  public void testReplaceEntry_presentNullValueUnsupported() {
    try {
      getMap().replace(k0(), v0(), null);
      fail("Expected NullPointerException");
    } catch (NullPointerException expected) {
    }
    expectUnchanged();
  }

  @MapFeature.Require(value = SUPPORTS_PUT, absent = ALLOWS_NULL_VALUE_QUERIES)

    }
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)
  public void testPut_unsupportedNotPresent() {
    try {
      put(e3());
      fail("put(notPresent, value) should throw");
    } catch (UnsupportedOperationException expected) {
    }
    expectUnchanged();
    expectMissing(e3());
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)

  }

  @MapFeature.Require(value = SUPPORTS_PUT, absent = ALLOWS_NULL_VALUES)
  public void testPutAllNullValueSingle_unsupported() {
    multimap().putAll(k1(), Lists.newArrayList((V) null));
    expectUnchanged();
  }

  // In principle, it would be nice to apply these two tests to keys with existing values, too.

  @MapFeature.Require(value = SUPPORTS_PUT, absent = ALLOWS_NULL_VALUES)

  @CollectionSize.Require(absent = ZERO)
  public void testReplaceEntry_presentNullValueUnsupported() {
    try {
      getMap().replace(k0(), v0(), null);
      fail("Expected NullPointerException");
    } catch (NullPointerException expected) {
    }
    expectUnchanged();
  }

  @MapFeature.Require(value = SUPPORTS_PUT, absent = ALLOWS_NULL_VALUE_QUERIES)

    List<V> values = Arrays.asList(v0(), v2(), v3());
    multimap().replaceValues(k0(), values);
    assertContentsAnyOrder(getCollection, v0(), v2(), v3());
  }

  @MapFeature.Require(absent = SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = ZERO)
  public void testReplaceValuesRemoveNotSupported() {
    List<V> values = Collections.singletonList(v3());
    try {
      multimap().replaceValues(k0(), values);