* values are merged using the specified merging function. If the merging function returns {@code
   * null}, then the collector removes the value that has been computed for the key thus far (though
   * future occurrences of the key would reinsert it).
   *
   * <p>Entries will appear in the encounter order of the first occurrence of the key.
   *

   * values are merged using the specified merging function. If the merging function returns {@code
   * null}, then the collector removes the value that has been computed for the key thus far (though
   * future occurrences of the key would reinsert it).
   *
   * <p>Entries will appear in the encounter order of the first occurrence of the key.
   *
   * @since 21.0
   */

  public ImmutableCollection<V> values() {
    if (cachedValues != null) {
      return cachedValues;
    }
    return cachedValues = createValues();
  }

  // cached so that this.multimapView().inverse() only computes inverse once
  private transient @Nullable ImmutableSetMultimap<K, V> multimapView;

  public ImmutableSetMultimap<K, V> asMultimap() {
    ImmutableSetMultimap<K, V> result = multimapView;
    return (result == null)