throw new AssertionError("Unknown type: " + type);
        }
        succeeded = true;
      } finally {
        if (!succeeded) { // When the visitation failed, we don't want to ignore the second.
          visited.remove(type);
        }
      }
    }
  }

  void visitClass(Class<?> t) {}

  void visitGenericArrayType(GenericArrayType t) {}

  void visitParameterizedType(ParameterizedType t) {}

 *       annotations that {@code ParametricNullness} was counteracting.
 * </ul>
 *
 * <p>This annotation is a temporary hack. We will remove it after <a
 * href="https://github.com/google/guava/issues/6126#issuecomment-1203145963">tools no longer need
 * it</a>.
 */
@GwtCompatible
@Retention(CLASS)
@Target({FIELD, METHOD, PARAMETER})

 *       annotations that {@code ParametricNullness} was counteracting.
 * </ul>
 *
 * <p>This annotation is a temporary hack. We will remove it after <a
 * href="https://github.com/google/guava/issues/6126#issuecomment-1203145963">tools no longer need
 * it</a>.
 */
@GwtCompatible
@Retention(CLASS)
@Target({FIELD, METHOD, PARAMETER})

 *       annotations that {@code ParametricNullness} was counteracting.
 * </ul>
 *
 * <p>This annotation is a temporary hack. We will remove it after <a
 * href="https://github.com/google/guava/issues/6126#issuecomment-1203145963">tools no longer need
 * it</a>.
 */
@GwtCompatible
@Retention(CLASS)
@Target({FIELD, METHOD, PARAMETER})

 *       annotations that {@code ParametricNullness} was counteracting.
 * </ul>
 *
 * <p>This annotation is a temporary hack. We will remove it after <a
 * href="https://github.com/google/guava/issues/6126#issuecomment-1203145963">tools no longer need
 * it</a>.
 */
@GwtCompatible
@Retention(CLASS)
@Target({FIELD, METHOD, PARAMETER})

 *       annotations that {@code ParametricNullness} was counteracting.
 * </ul>
 *
 * <p>This annotation is a temporary hack. We will remove it after <a
 * href="https://github.com/google/guava/issues/6126#issuecomment-1203145963">tools no longer need
 * it</a>.
 */
@GwtCompatible
@Retention(CLASS)
@Target({FIELD, METHOD, PARAMETER})

 *       annotations that {@code ParametricNullness} was counteracting.
 * </ul>
 *
 * <p>This annotation is a temporary hack. We will remove it after <a
 * href="https://github.com/google/guava/issues/6126#issuecomment-1203145963">tools no longer need
 * it</a>.
 */
@GwtCompatible
@Retention(CLASS)
@Target({FIELD, METHOD, PARAMETER})

 *       annotations that {@code ParametricNullness} was counteracting.
 * </ul>
 *
 * <p>This annotation is a temporary hack. We will remove it after <a
 * href="https://github.com/google/guava/issues/6126#issuecomment-1203145963">tools no longer need
 * it</a>.
 */
@GwtCompatible
@Retention(CLASS)
@Target({FIELD, METHOD, PARAMETER})

  public void removePredecessor(N node) {
    @SuppressWarnings("unused")
    V unused = removeSuccessor(node);
  }

  @Override
  public @Nullable V removeSuccessor(N node) {
    return adjacentNodeValues.remove(node);
  }

  @Override
  public void addPredecessor(N node, V value) {
    @SuppressWarnings("unused")
    V unused = addSuccessor(node, value);
  }

  @Override

    EnumBiMap<Currency, Country> bimap = EnumBiMap.create(map);

    Iterator<Currency> iter = bimap.keySet().iterator();
    assertEquals(Currency.DOLLAR, iter.next());
    iter.remove();

    // forward map ordered by currency
    assertThat(bimap.keySet()).containsExactly(Currency.FRANC, Currency.PESO).inOrder();
    // forward map ordered by currency (even for country values)