this.inverse = inverse;
  }

  // Query Operations (optimizations)

  @Override
  public boolean containsValue(@CheckForNull Object value) {
    return inverse.containsKey(value);
  }

  // Modification Operations

  @CanIgnoreReturnValue
  @Override
  @CheckForNull
  public V put(@ParametricNullness K key, @ParametricNullness V value) {
    return putInBothMaps(key, value, false);
  }

 * present in the map to be reclaimed by the garbage collector. Entries with reclaimed keys or
 * values may be removed from the map on each map modification or on occasional map accesses; such
 * entries may be counted by {@link Map#size}, but will never be visible to read or write
 * operations. A partially-reclaimed entry is never exposed to the user. Any {@link Map.Entry}

 * }</pre>
 *
 * <h3>Views</h3>
 *
 * <p>Much of the power of the multimap API comes from the <i>view collections</i> it provides.
 * These always reflect the latest state of the multimap itself. When they support modification, the
 * changes are <i>write-through</i> (they automatically update the backing multimap). These view
 * collections are:
 *
 * <ul>
 *   <li>{@link #asMap}, mentioned above

 * present in the map to be reclaimed by the garbage collector. Entries with reclaimed keys or
 * values may be removed from the map on each map modification or on occasional map accesses; such
 * entries may be counted by {@link Map#size}, but will never be visible to read or write
 * operations. A partially-reclaimed entry is never exposed to the user. Any {@link Map.Entry}

   * concurrent modification, the iterator fails quickly and cleanly, rather than risking arbitrary,
   * non-deterministic behavior at an undetermined time in the future.
   *
   * <p>Note that the fail-fast behavior of an iterator cannot be guaranteed as it is, generally
   * speaking, impossible to make any hard guarantees in the presence of unsynchronized concurrent

      /*
       * requireNonNull is safe as long as callers pass a nextSibling that (a) has the same key and
       * (b) is present in the multimap. (And they do, except maybe in case of concurrent
       * modification, in which case all bets are off.)
       */
      KeyList<K, V> keyList = requireNonNull(keyToKeyList.get(key));
      keyList.count++;
      node.previous = nextSibling.previous;

   * lists are sublist views of the original list, produced on demand using {@link List#subList(int,
   * int)}, and are subject to all the usual caveats about modification as explained in that API.
   *
   * @param list the list to return consecutive sublists of
   * @param size the desired size of each sublist (the last may be smaller)
   * @return a list of consecutive sublists

   * allocated, the value of {@code metadata} combines the number of bits in the "short hash", in
   * its bottom {@value CompactHashing#HASH_TABLE_BITS_MAX_BITS} bits, with a modification count in
   * the remaining bits that is used to detect concurrent modification during iteration.
   */
  private transient int metadata;

  /** The number of elements contained in the set. */
  private transient int size;

   * #add(Range) add} any range not {@linkplain Range#encloses(Range) enclosed} by {@code view}.
   */
  RangeSet<C> subRangeSet(Range<C> view);

  // Modification

  /**
   * Adds the specified range to this {@code RangeSet} (optional operation). That is, for equal
   * range sets a and b, the result of {@code a.add(range)} is that {@code a} will be the minimal

  @Override
  public int count(@CheckForNull Object element) {
    Count frequency = Maps.safeGet(backingMap, element);
    return (frequency == null) ? 0 : frequency.get();
  }

  // Optional Operations - Modification Operations

  /**
   * {@inheritDoc}
   *
   * @throws IllegalArgumentException if the call would result in more than {@link
   *     Integer#MAX_VALUE} occurrences of {@code element} in this multiset.
   */