@Override
    public boolean remove(@Nullable Object key, @Nullable Object value) {
      throw new UnsupportedOperationException();
    }

    @Override
    public boolean replace(K key, V oldValue, V newValue) {
      throw new UnsupportedOperationException();
    }

    @Override
    public @Nullable V replace(K key, V value) {
      throw new UnsupportedOperationException();
    }

  public void testReplaceValuesWithEmpty() {
    int size = multimap().size();
    List<V> oldValues = new ArrayList<>(multimap().get(k0()));
    List<V> values = emptyList();
    assertEquals(oldValues, new ArrayList<V>(multimap().replaceValues(k0(), values)));
    assertGet(k0());
    assertEquals(size - oldValues.size(), multimap().size());
  }

  @MapFeature.Require({SUPPORTS_PUT, SUPPORTS_REMOVE})

  public void testReplaceValuesWithEmpty() {
    int size = multimap().size();
    List<V> oldValues = new ArrayList<>(multimap().get(k0()));
    List<V> values = emptyList();
    assertEquals(oldValues, new ArrayList<V>(multimap().replaceValues(k0(), values)));
    assertGet(k0());
    assertEquals(size - oldValues.size(), multimap().size());
  }

  @MapFeature.Require({SUPPORTS_PUT, SUPPORTS_REMOVE})

     * But that check wouldn't eliminate the warnings.)
     */
    @SuppressWarnings({"unchecked", "nullness"})
    K castKey = (K) key;
    List<V> oldValues = getCopy(castKey);
    removeAllNodes(castKey);
    return oldValues;
  }

  @Override
  public void clear() {
    head = null;
    tail = null;
    keyToKeyList.clear();
    size = 0;
    modCount++;
  }

     * But that check wouldn't eliminate the warnings.)
     */
    @SuppressWarnings({"unchecked", "nullness"})
    K castKey = (K) key;
    List<V> oldValues = getCopy(castKey);
    removeAllNodes(castKey);
    return oldValues;
  }

  @Override
  public void clear() {
    head = null;
    tail = null;
    keyToKeyList.clear();
    size = 0;
    modCount++;
  }

    Collection<V> oldValues = createCollection();
    oldValues.addAll(collection);

    totalSize -= collection.size();
    collection.clear();

    while (iterator.hasNext()) {
      if (collection.add(iterator.next())) {
        totalSize++;
      }
    }

    return unmodifiableCollectionSubclass(oldValues);
  }

  /**
   * {@inheritDoc}
   *

    Collection<V> oldValues = createCollection();
    oldValues.addAll(collection);

    totalSize -= collection.size();
    collection.clear();

    while (iterator.hasNext()) {
      if (collection.add(iterator.next())) {
        totalSize++;
      }
    }

    return unmodifiableCollectionSubclass(oldValues);
  }

  /**
   * {@inheritDoc}
   *