while (entryItr.hasNext()) {
      Entry<K, V> entry = entryItr.next();
      entry.setValue(e3().getValue());
      entryItr.remove();
    }
    assertTrue(getMap().isEmpty());
  }

  public void testContainsEntryWithIncomparableKey() {
    try {
      assertFalse(getMap().entrySet().contains(mapEntry(IncomparableType.INSTANCE, v0())));
    } catch (ClassCastException acceptable) {

    while (entryItr.hasNext()) {
      Entry<K, V> entry = entryItr.next();
      entry.setValue(e3().getValue());
      entryItr.remove();
    }
    assertTrue(getMap().isEmpty());
  }

  public void testContainsEntryWithIncomparableKey() {
    try {
      assertFalse(getMap().entrySet().contains(mapEntry(IncomparableType.INSTANCE, v0())));
    } catch (ClassCastException acceptable) {

    resetWithHole();
    assertEquals(a, navigableMap.floorEntry(a.getKey()));
    assertEquals(a.getKey(), navigableMap.floorKey(a.getKey()));
    assertEquals(a, navigableMap.floorEntry(b.getKey()));
    assertEquals(a.getKey(), navigableMap.floorKey(b.getKey()));
    assertEquals(c, navigableMap.floorEntry(c.getKey()));
    assertEquals(c.getKey(), navigableMap.floorKey(c.getKey()));
  }

  @CollectionSize.Require(SEVERAL)

        "putIfAbsent(notPresent, value) should return null", getMap().putIfAbsent(k3(), v3()));
    expectAdded(e3());
  }

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testPutIfAbsent_supportedPresent() {
    assertEquals(
        "putIfAbsent(present, value) should return existing value",
        v0(),
        getMap().putIfAbsent(k0(), v3()));
    expectUnchanged();
  }

    assertEquals(c.getKey(), navigableMap.lastKey());
  }

  @CollectionSize.Require(absent = ZERO)
  public void testHeadMapExclusive() {
    assertFalse(navigableMap.headMap(a.getKey()).containsKey(a.getKey()));
  }

  @CollectionSize.Require(absent = ZERO)
  public void testTailMapInclusive() {
    assertTrue(navigableMap.tailMap(a.getKey()).containsKey(a.getKey()));
  }

  public void testHeadMap() {

        "putIfAbsent(notPresent, value) should return null", getMap().putIfAbsent(k3(), v3()));
    expectAdded(e3());
  }

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testPutIfAbsent_supportedPresent() {
    assertEquals(
        "putIfAbsent(present, value) should return existing value",
        v0(),
        getMap().putIfAbsent(k0(), v3()));
    expectUnchanged();
  }

    assertEquals(c.getKey(), navigableMap.lastKey());
  }

  @CollectionSize.Require(absent = ZERO)
  public void testHeadMapExclusive() {
    assertFalse(navigableMap.headMap(a.getKey()).containsKey(a.getKey()));
  }

  @CollectionSize.Require(absent = ZERO)
  public void testTailMapInclusive() {
    assertTrue(navigableMap.tailMap(a.getKey()).containsKey(a.getKey()));
  }

  public void testHeadMap() {

    assertNull("put(null, null) should return null", put(nullKeyValueEntry));
    expectAdded(nullKeyValueEntry);
  }

  @CanIgnoreReturnValue
  private V put(Entry<K, V> entry) {
    return getMap().put(entry.getKey(), entry.getValue());
  }

  /**
   * Returns the {@link Method} instance for {@link #testPut_nullKeyUnsupported()} so that tests of
   * {@link java.util.TreeMap} can suppress it with {@code

  public void testPutAll_nullCollectionReference() {
    assertThrows(NullPointerException.class, () -> getMap().putAll(null));
  }

  private void putAll(Iterable<Entry<K, V>> entries) {
    Map<K, V> map = new LinkedHashMap<>();
    for (Entry<K, V> entry : entries) {
      map.put(entry.getKey(), entry.getValue());
    }
    getMap().putAll(map);
  }

  /**

    assertNull("put(null, null) should return null", put(nullKeyValueEntry));
    expectAdded(nullKeyValueEntry);
  }

  @CanIgnoreReturnValue
  private V put(Entry<K, V> entry) {
    return getMap().put(entry.getKey(), entry.getValue());
  }

  /**
   * Returns the {@link Method} instance for {@link #testPut_nullKeyUnsupported()} so that tests of
   * {@link java.util.TreeMap} can suppress it with {@code