* the key entry's prev or next pointer might point to the dead value entry, and when we
     * put the new entry in the key entry's position in iteration order, it might invalidate
     * the linked list.
     */

    if (oldEntryForValue != null) {
      delete(oldEntryForValue);
    }

    if (oldEntryForKey != null) {
      delete(oldEntryForKey);
    }

      Map<R, Map<C, V>> backingMap, Supplier<? extends Map<C, V>> factory) {
    checkArgument(backingMap.isEmpty());
    checkNotNull(factory);
    // TODO(jlevy): Wrap factory to validate that the supplied maps are empty?
    return new StandardTable<>(backingMap, factory);
  }

  /**
   * Returns a view of a table where each value is transformed by a function. All other properties

  private enum Validator {
    NON_CACHING_WITH_CONSTRUCTOR_CHECK(nonCachingWithConstructorCheckValidator()),
    NON_CACHING_WITHOUT_CONSTRUCTOR_CHECK(nonCachingWithoutConstructorCheckValidator()),
    WEAK_SET(weakSetValidator()),
    CLASS_VALUE(classValueValidator()),
    ;

    final GetCheckedTypeValidator validator;

    Validator(GetCheckedTypeValidator validator) {
      this.validator = validator;
    }

  }

  public void testApply() {
    when(mock.apply("key")).thenReturn(Boolean.TRUE);
    assertSame(Boolean.TRUE, forward.apply("key"));
  }

  public void testInvalidate() {
    forward.invalidate("key");
    verify(mock).invalidate("key");
  }

  public void testRefresh() throws ExecutionException {
    forward.refresh("key");
    verify(mock).refresh("key");
  }

  public void testInvalidateAll() {

  }


  public void testInvalidate_empty() {
    for (LoadingCache<Object, Object> cache : caches()) {
      cache.getUnchecked("a");
      cache.getUnchecked("b");
      cache.invalidate("a");
      cache.invalidate("b");
      cache.invalidate(0);
      checkEmpty(cache);
    }
  }

  public void testInvalidateAll_empty() {
    for (LoadingCache<Object, Object> cache : caches()) {
      cache.getUnchecked("a");

    assertThat(wrappedSet).isEqualTo(copyOfWrappedSet);

    // test that setToTest is still valid
    assertThat(setToTest).isEqualTo(wrappedSet);
    assertThat(setToTest).isEqualTo(copyOfWrappedSet);

    // invalidate setToTest
    wrappedSet.remove(1);
    // sanity check on update of wrappedSet
    assertThat(wrappedSet).isNotEqualTo(copyOfWrappedSet);

    assertThat(wrappedSet).isEqualTo(copyOfWrappedSet);

    // test that setToTest is still valid
    assertThat(setToTest).isEqualTo(wrappedSet);
    assertThat(setToTest).isEqualTo(copyOfWrappedSet);

    // invalidate setToTest
    wrappedSet.remove(1);
    // sanity check on update of wrappedSet
    assertThat(wrappedSet).isNotEqualTo(copyOfWrappedSet);

 * @since 10.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public enum RemovalCause {
  /**
   * The entry was manually removed by the user. This can result from the user invoking {@link
   * Cache#invalidate}, {@link Cache#invalidateAll(Iterable)}, {@link Cache#invalidateAll()}, {@link
   * Map#remove}, {@link ConcurrentMap#remove}, or {@link Iterator#remove}.
   */
  EXPLICIT {
    @Override
    boolean wasEvicted() {

   */
  ALLOWS_NULL_QUERIES,
  ALLOWS_NULL_VALUES(ALLOWS_NULL_QUERIES),

  /**
   * Indicates that a collection disallows certain elements (other than {@code null}, whose validity
   * as an element is indicated by the presence or absence of {@link #ALLOWS_NULL_VALUES}). From the
   * documentation for {@link Collection}:
   *
   * <blockquote>
   *

          @Override
          public Integer getIfPresent(Object key) {
            throw new UnsupportedOperationException();
          }

          @Override
          public void invalidate(Object key) {
            invalidated.add(key);
          }
        };

    List<Integer> toInvalidate = ImmutableList.of(1, 2, 3, 4);
    cache.invalidateAll(toInvalidate);