@CollectionFeature.Require(SUPPORTS_ADD)
  public void testElementSetReflectsAddAbsent() {
    Set<E> elementSet = getMultiset().elementSet();
    assertFalse(elementSet.contains(e3()));
    getMultiset().add(e3(), 4);
    assertTrue(elementSet.contains(e3()));
  }

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

  @CollectionFeature.Require(SUPPORTS_ADD)
  @CollectionSize.Require(absent = ZERO)
  public void testAddAll_supportedAllPresent() {
    assertTrue(
        "addAll(allPresent) should return true", getList().addAll(MinimalCollection.of(e0())));
    expectAdded(e0());
  }

  @CollectionFeature.Require(absent = SUPPORTS_ADD)
  @CollectionSize.Require(absent = ZERO)

  @ListFeature.Require(SUPPORTS_SET)
  @CollectionSize.Require(absent = ZERO)
  public void testSet() {
    doTestSet(e3());
  }

  @CollectionSize.Require(absent = ZERO)
  @CollectionFeature.Require(ALLOWS_NULL_VALUES)
  @ListFeature.Require(SUPPORTS_SET)
  public void testSet_null() {
    doTestSet(null);
  }

  @CollectionSize.Require(absent = ZERO)

  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testRemove_notPresent() {
    assertNull("remove(notPresent) should return null", getMap().remove(k3()));
    expectUnchanged();
  }

  @MapFeature.Require({SUPPORTS_REMOVE, ALLOWS_NULL_KEYS})
  @CollectionSize.Require(absent = ZERO)
  public void testRemove_nullPresent() {
    initMapWithNullKey();

    int initialSize = getMap().size();
    assertEquals(

                (k, v) -> {
                  throw new AssertionFailedError();
                }));
    expectUnchanged();
  }

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testComputeIfPresent_supportedPresent() {
    assertEquals(
        "computeIfPresent(present, function) should return new value",
        v3(),
        getMap()
            .computeIfPresent(
                k0(),

    return (ConcurrentMap<K, V>) super.getMap();
  }

  @MapFeature.Require(SUPPORTS_PUT)
  public void testPutIfAbsent_supportedAbsent() {
    assertNull("putIfAbsent(notPresent, value) should return null", putIfAbsent(e3()));
    expectAdded(e3());
  }

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testPutIfAbsent_supportedPresent() {
    assertEquals(

    }
  }

  @MapFeature.Require(ALLOWS_NULL_KEYS)
  @CollectionSize.Require(absent = ZERO)
  public void testGetOrDefault_nonNullWhenNullContained() {
    initMapWithNullKey();
    assertEquals(
        "getOrDefault(absent, default) should return default",
        v3(),
        getMap().getOrDefault(k3(), v3()));
  }

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

    assertEquals(2, multimap().size());
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testPropagatesRemoveLastElementToMultimap() {
    Collection<V> result = multimap().asMap().get(k0());
    assertTrue(result.remove(v0()));
    assertGet(k0());
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testPropagatesClearToMultimap() {

  }

  public void testGetTesterAnnotations_class() {
    @Require
    @NotTesterAnnotation
    class Tester {}

    assertThat(getTesterAnnotations(Tester.class))
        .containsExactly(Tester.class.getAnnotation(Require.class));
  }

  public void testGetTesterAnnotations_method() throws Exception {
    class Tester {
      @Keep
      @Require
      @NotTesterAnnotation
      public void test() {}
    }

  // Incorrect expected present count.

  @CollectionFeature.Require(SUPPORTS_ADD)
  public void testSetCountConditional_oldCountTooLarge() {
    assertFalse(
        "setCount() with a too-large oldCount should return false",
        getMultiset().setCount(e0(), 2, 3));
    expectUnchanged();
  }

  @CollectionSize.Require(absent = ZERO)
  @CollectionFeature.Require(SUPPORTS_ADD)