}

  @CollectionFeature.Require(ALLOWS_NULL_QUERIES)
  public void testCount_nullAbsent() {
    assertEquals("multiset.count(null) didn't return 0", 0, getMultiset().count(null));
  }

  @CollectionFeature.Require(absent = ALLOWS_NULL_QUERIES)
  public void testCount_null_forbidden() {
    try {
      getMultiset().count(null);

    setCount(element, count);
  }

  @CanIgnoreReturnValue
  private boolean setCount(E element, int count) {
    return getMultiset().setCount(element, getMultiset().count(element), count);
  }

  private void assertSetCountNegativeOldCount() {
    try {
      getMultiset().setCount(e3(), -1, 1);
      fail("calling setCount() with a negative oldCount should throw IllegalArgumentException");

 */
@GwtCompatible
@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
public class AbstractMultisetTester<E> extends AbstractCollectionTester<E> {
  protected final Multiset<E> getMultiset() {
    return (Multiset<E>) collection;
  }

  protected void initThreeCopies() {
    collection = getSubjectGenerator().create(e0(), e0(), e0());
  }

  public void testEntrySetSerialization() {
    Set<Multiset.Entry<E>> expected = getMultiset().entrySet();
    assertEquals(expected, SerializableTester.reserialize(expected));
  }

  @CollectionFeature.Require(SERIALIZABLE_INCLUDING_VIEWS)
  public void testElementSetSerialization() {
    Set<E> expected = getMultiset().elementSet();
    assertEquals(expected, SerializableTester.reserialize(expected));
  }

    initThreeCopies();
    assertEquals(3, getMultiset().count(e0()));
    Multiset.Entry<E> entry = Iterables.getOnlyElement(getMultiset().entrySet());
    assertEquals(3, entry.getCount());
    assertTrue(getMultiset().remove(e0()));
    assertEquals(2, entry.getCount());
    assertTrue(getMultiset().elementSet().remove(e0()));
    assertEquals(0, entry.getCount());
    getMultiset().add(e0(), 2);
    assertEquals(2, entry.getCount());

    assertEquals(expectedSize, getMultiset().size());
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  public void testElementSetRemoveAbsent() {
    Set<E> elementSet = getMultiset().elementSet();
    assertFalse(elementSet.remove(e3()));
    expectUnchanged();
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  public void testElementSetClear() {
    getMultiset().elementSet().clear();

  @CollectionSize.Require(absent = ZERO)
  public void testContainsAllMultisetIgnoresFrequency() {
    assertTrue(getMultiset().containsAll(getSubjectGenerator().create(e0(), e0(), e0())));
  }

  @CollectionSize.Require(absent = ZERO)
  public void testContainsAllListIgnoresFrequency() {
    assertTrue(getMultiset().containsAll(Arrays.asList(e0(), e0(), e0())));
  }

  public void testEntrySetSerialization() {
    Set<Multiset.Entry<E>> expected = getMultiset().entrySet();
    assertEquals(expected, SerializableTester.reserialize(expected));
  }

  @CollectionFeature.Require(SERIALIZABLE_INCLUDING_VIEWS)
  public void testElementSetSerialization() {
    Set<E> expected = getMultiset().elementSet();
    assertEquals(expected, SerializableTester.reserialize(expected));
  }

    assertEquals(getMultiset().entrySet().hashCode(), getMultiset().hashCode());
  }

  @CollectionSize.Require(absent = ZERO)
  @CollectionFeature.Require(ALLOWS_NULL_VALUES)
  public void testEqualsMultisetWithNullValue() {
    new EqualsTester()
        .addEqualityGroup(getMultiset())
        .addEqualityGroup(
            getSubjectGenerator().create(createArrayWithNullElement()),

    setCount(element, count);
  }

  @CanIgnoreReturnValue
  private boolean setCount(E element, int count) {
    return getMultiset().setCount(element, getMultiset().count(element), count);
  }

  private void assertSetCountNegativeOldCount() {
    try {
      getMultiset().setCount(e3(), -1, 1);
      fail("calling setCount() with a negative oldCount should throw IllegalArgumentException");