"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();
  }

    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()));

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

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

    try {
      assertEquals(v0(), getMap().replace(k0(), v3()));
      expectReplacement(entry(k0(), v3()));
    } catch (ClassCastException tolerated) { // for ClassToInstanceMap
      expectUnchanged();
    }
  }

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testReplace_supportedPresentNoChange() {
    assertEquals(v0(), getMap().replace(k0(), v0()));
    expectUnchanged();

    assertTrue("containsKey(present) should return true", getMap().containsKey(k0()));
  }

  public void testContains_no() {
    assertFalse("containsKey(notPresent) should return false", getMap().containsKey(k3()));
  }

  @MapFeature.Require(ALLOWS_NULL_KEY_QUERIES)
  public void testContains_nullNotContainedButAllowed() {
    assertFalse("containsKey(null) should return false", getMap().containsKey(null));
  }

public class BiMapEntrySetTester<K, V> extends AbstractBiMapTester<K, V> {
  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testSetValue_valueAbsent() {
    for (Entry<K, V> entry : getMap().entrySet()) {
      if (entry.getKey().equals(k0())) {
        assertEquals("entry.setValue() should return the old value", v0(), entry.setValue(v3()));
      }
    }
    expectReplacement(entry(k0(), v3()));
  }

  @CollectionSize.Require(ZERO)
  public void testIsEmpty_yes() {
    assertTrue("isEmpty() should return true", getMap().isEmpty());
  }

  @CollectionSize.Require(absent = ZERO)
  public void testIsEmpty_no() {
    assertFalse("isEmpty() should return false", getMap().isEmpty());
  }

    Set<Object> observed = Sets.newIdentityHashSet(); // for the sake of weakly referenced locks.
    // this gets the stripes with #getAt(index)
    for (int i = 0; i < striped.size(); i++) {
      Object object = striped.getAt(i);
      assertNotNull(object);
      assertSame(object, striped.getAt(i)); // idempotent
      observed.add(object);
    }
    assertTrue("All stripes observed", observed.size() == striped.size());

    for (Entry<K, V> entry : getSampleEntries()) {
      expectedHashCode += hash(entry);
    }
    assertEquals(
        "A Map's hashCode() should be the sum of those of its entries.",
        expectedHashCode,
        getMap().hashCode());
  }

  @CollectionSize.Require(absent = CollectionSize.ZERO)
  @MapFeature.Require(ALLOWS_NULL_KEYS)
  public void testHashCode_containingNullKey() {
    Entry<K, V> entryWithNull = entry(null, v3());

    for (Entry<K, V> entry : getSampleEntries()) {
      expectedHashCode += hash(entry);
    }
    assertEquals(
        "A Map's hashCode() should be the sum of those of its entries.",
        expectedHashCode,
        getMap().hashCode());
  }

  @CollectionSize.Require(absent = CollectionSize.ZERO)
  @MapFeature.Require(ALLOWS_NULL_KEYS)
  public void testHashCode_containingNullKey() {
    Entry<K, V> entryWithNull = entry(null, v3());