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)

        "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();
  }

  @MapFeature.Require(SUPPORTS_PUT)
  public void testComputeIfAbsent_supportedAbsent() {
    assertEquals(
        "computeIfAbsent(notPresent, function) should return new value",
        v3(),
        getMap()
            .computeIfAbsent(
                k3(),
                k -> {
                  assertEquals(k3(), k);
                  return v3();
                }));
    expectAdded(e3());
  }

        v3(),
        getMap()
            .compute(
                k3(),
                (k, v) -> {
                  assertEquals(k3(), k);
                  assertNull(v);
                  return v3();
                }));
    expectAdded(e3());
    assertEquals(getNumElements() + 1, getMap().size());
  }

  @MapFeature.Require({SUPPORTS_PUT, SUPPORTS_REMOVE})

        v3(),
        getMap()
            .compute(
                k3(),
                (k, v) -> {
                  assertEquals(k3(), k);
                  assertNull(v);
                  return v3();
                }));
    expectAdded(e3());
    assertEquals(getNumElements() + 1, getMap().size());
  }

  @MapFeature.Require({SUPPORTS_PUT, SUPPORTS_REMOVE})

    assertTrue(getMap().remove(k0(), v0()));
    expectMissing(e0());
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testRemove_supportedPresentKeyWrongValue() {
    assertFalse(getMap().remove(k0(), v3()));
    expectUnchanged();
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testRemove_supportedWrongKeyPresentValue() {
    assertFalse(getMap().remove(k3(), v0()));

public class MapClearTester<K, V> extends AbstractMapTester<K, V> {
  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testClear() {
    getMap().clear();
    assertTrue("After clear(), a map should be empty.", getMap().isEmpty());
    assertEquals(0, getMap().size());
    assertFalse(getMap().entrySet().iterator().hasNext());
  }

  @MapFeature.Require({FAILS_FAST_ON_CONCURRENT_MODIFICATION, SUPPORTS_REMOVE})

  @MapFeature.Require(SUPPORTS_PUT)
  public void testAbsent() {
    assertEquals(
        "Map.merge(absent, value, function) should return value",
        v3(),
        getMap()
            .merge(
                k3(),
                v3(),
                (oldV, newV) -> {
                  throw new AssertionFailedError(

    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) {