public void testMergeNullFunction() {
    try {
      getMap().merge(k0(), v3(), null);
      fail("Expected NullPointerException or UnsupportedOperationException");
    } catch (NullPointerException | UnsupportedOperationException expected) {
    }
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)
  public void testMergeUnsupported() {
    try {
      getMap()
          .merge(
              k3(),

    extends AbstractContainerTester<Map<K, V>, Entry<K, V>> {
  protected Map<K, V> getMap() {
    return container;
  }

  @Override
  protected Collection<Entry<K, V>> actualContents() {
    return getMap().entrySet();
  }

  /** @see AbstractContainerTester#resetContainer() */
  protected final void resetMap() {
    resetContainer();
  }

  }

  @MapFeature.Require(SUPPORTS_PUT)
  public void testPutAll_supportedNothing() {
    getMap().putAll(emptyMap());
    expectUnchanged();
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)
  public void testPutAll_unsupportedNothing() {
    try {
      getMap().putAll(emptyMap());
    } catch (UnsupportedOperationException tolerated) {
    }
    expectUnchanged();
  }

      assertEquivalent(stats.mean(), streamStats.getAverage());
      assertEquivalent(stats.sum(), streamStats.getSum());
      assertEquivalent(stats.max(), streamStats.getMax());
      assertEquivalent(stats.min(), streamStats.getMin());
    }
  }

  private static void assertEquivalent(double actual, double expected) {
    if (expected == POSITIVE_INFINITY) {

  @CollectionSize.Require(absent = ZERO)
  public void testRemove_present() {
    int initialSize = getMap().size();
    assertEquals("remove(present) should return the associated value", v0(), getMap().remove(k0()));
    assertEquals(
        "remove(present) should decrease a map's size by one.", initialSize - 1, getMap().size());
    expectMissing(e0());
  }

  public void testKeySetIteratorRemove() {
    int initialSize = getNumElements();
    Iterator<K> iterator = getMap().keySet().iterator();
    iterator.next();
    iterator.remove();
    assertEquals(initialSize - 1, getMap().size());
    assertEquals(initialSize - 1, getMap().inverse().size());
  }

  public void testKeySetIteratorRemove() {
    int initialSize = getNumElements();
    Iterator<K> iterator = getMap().keySet().iterator();
    iterator.next();
    iterator.remove();
    assertEquals(initialSize - 1, getMap().size());
    assertEquals(initialSize - 1, getMap().inverse().size());
  }

public class ConcurrentMapRemoveTester<K, V> extends AbstractMapTester<K, V> {
  @Override
  protected ConcurrentMap<K, V> getMap() {
    return (ConcurrentMap<K, V>) super.getMap();
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = ZERO)
  public void testRemove_supportedPresent() {
    assertTrue(getMap().remove(k0(), v0()));
    expectMissing(e0());
  }

  @MapFeature.Require(SUPPORTS_REMOVE)

public class ConcurrentMapRemoveTester<K, V> extends AbstractMapTester<K, V> {
  @Override
  protected ConcurrentMap<K, V> getMap() {
    return (ConcurrentMap<K, V>) super.getMap();
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = ZERO)
  public void testRemove_supportedPresent() {
    assertTrue(getMap().remove(k0(), v0()));
    expectMissing(e0());
  }

  @MapFeature.Require(SUPPORTS_REMOVE)

    Set<Entry<K, V>> entrySet = getMap().entrySet();
    Iterator<Entry<K, V>> entryItr = entrySet.iterator();
    assertEquals(e0(), entryItr.next());
    entryItr.remove();
    assertTrue(getMap().isEmpty());
    assertFalse(entrySet.contains(e0()));
  }

  public void testContainsEntryWithIncomparableKey() {
    try {