Multiset<N> adjacentNodes = getReference(adjacentNodesReference);
    if (adjacentNodes != null) {
      checkState(adjacentNodes.add(node));
    }
  }

  @CheckForNull
  private static <T> T getReference(@CheckForNull Reference<T> reference) {
    return (reference == null) ? null : reference.get();
  }

   * @since 20.0 (varargs overload since 2.0)
   */
  @CanIgnoreReturnValue
  public static <T> T checkNotNull(
      @CheckForNull T reference,
      String errorMessageTemplate,
      @CheckForNull Object p1,
      @CheckForNull Object p2,
      @CheckForNull Object p3,
      @CheckForNull Object p4) {
    if (reference == null) {
      throw new NullPointerException(lenientFormat(errorMessageTemplate, p1, p2, p3, p4));

   *
   * @return the converted value; is null <i>if and only if</i> {@code a} is null
   */
  @CheckForNull
  public final B convert(@CheckForNull A a) {
    return correctedDoForward(a);
  }

  @CheckForNull
  B correctedDoForward(@CheckForNull A a) {
    if (handleNullAutomatically) {
      // TODO(kevinb): we shouldn't be checking for a null result at runtime. Assert?

    throw new UnsupportedOperationException();
  }

  @CanIgnoreReturnValue
  @Override
  public final boolean remove(@CheckForNull Object element) {
    return remove(element, 1) > 0;
  }

  @CanIgnoreReturnValue
  @Override
  public int remove(@CheckForNull Object element, int occurrences) {
    throw new UnsupportedOperationException();
  }

  @CanIgnoreReturnValue
  @Override

   * forward to this implementation.
   */
  @CheckForNull
  protected Entry<E> standardFirstEntry() {
    Iterator<Entry<E>> entryIterator = entrySet().iterator();
    if (!entryIterator.hasNext()) {
      return null;
    }
    Entry<E> entry = entryIterator.next();
    return Multisets.immutableEntry(entry.getElement(), entry.getCount());
  }

  @Override
  @CheckForNull
  public Entry<E> lastEntry() {

    }

    @CheckForNull
    abstract V getValue(int keyIndex);

    @Override
    ImmutableSet<K> createKeySet() {
      return isFull() ? keyToIndex().keySet() : super.createKeySet();
    }

    @Override
    public int size() {
      return size;
    }

    @Override
    @CheckForNull
    public V get(@CheckForNull Object key) {

    return size() == 0;
  }

  @Override
  public boolean containsValue(@CheckForNull Object value) {
    for (Collection<V> collection : asMap().values()) {
      if (collection.contains(value)) {
        return true;
      }
    }

    return false;
  }

  @Override
  public boolean containsEntry(@CheckForNull Object key, @CheckForNull Object value) {
    Collection<V> collection = asMap().get(key);

  }

  @Override
  @CheckForNull
  public E lower(E element) {
    return forward.higher(element);
  }

  @Override
  @CheckForNull
  public E floor(E element) {
    return forward.ceiling(element);
  }

  @Override
  @CheckForNull
  public E ceiling(E element) {
    return forward.floor(element);
  }

  @Override
  @CheckForNull
  public E higher(E element) {

  public UncheckedTimeoutException() {}

  public UncheckedTimeoutException(@CheckForNull String message) {
    super(message);
  }

  public UncheckedTimeoutException(@CheckForNull Throwable cause) {
    super(cause);
  }

  public UncheckedTimeoutException(@CheckForNull String message, @CheckForNull Throwable cause) {
    super(message, cause);
  }

  private static final long serialVersionUID = 0;

      return Ordering.<Cut<C>>natural();
    }

    @Override
    public boolean containsKey(@CheckForNull Object key) {
      return get(key) != null;
    }

    @Override
    @CheckForNull
    public Range<C> get(@CheckForNull Object key) {
      if (key instanceof Cut) {
        try {
          @SuppressWarnings("unchecked") // we catch CCEs