*       instances.
   *   <li>For the constructor or static factory method used to construct instances, it's checked
   *       that when equal parameters are passed, the result instance should also be equal; and vice
   *       versa.
   *   <li>If a non-private constructor or non-private static factory method exists:
   *       <ul>
   *         <li>Test will fail if default value for a parameter cannot be determined.

   *       instances.
   *   <li>For the constructor or static factory method used to construct instances, it's checked
   *       that when equal parameters are passed, the result instance should also be equal; and vice
   *       versa.
   *   <li>If a non-private constructor or non-private static factory method exists:
   *       <ul>
   *         <li>Test will fail if default value for a parameter cannot be determined.

   * <i>adding</i> to the returned set is not possible.
   */
  @Override
  public Set<K> keySet() {
    return super.keySet();
  }

  /**
   * Returns a collection of all values in the multimap. Changes to the returned collection will
   * update the underlying multimap, and vice versa.
   *

   * the table lacks a mapping for a given row and column, the corresponding array element is null.
   *
   * <p>Subsequent table changes will not modify the array, and vice versa.
   *
   * @param valueClass class of values stored in the returned array
   */
  @GwtIncompatible // reflection
  public @Nullable V[][] toArray(Class<V> valueClass) {

   */
  public abstract double transform(double x);

  /**
   * Returns the inverse linear transformation. The inverse of a horizontal transformation is a
   * vertical transformation, and vice versa. The inverse of the {@link #forNaN} transformation is
   * itself. In all other cases, the inverse is a transformation such that applying both the

   * Returns a list that applies {@code function} to each element of {@code fromList}. The returned
   * list is a transformed view of {@code fromList}; changes to {@code fromList} will be reflected
   * in the returned list and vice versa.
   *
   * <p>Since functions are not reversible, the transform is one-way and new items cannot be stored
   * in the returned list. The {@code add}, {@code addAll} and {@code set} methods are unsupported

  /*
   * We have some considerable complexity in these create methods because of
   * Builder.buildKeepingLast(). The same Builder might be called with buildKeepingLast() and then
   * buildOrThrow(), or vice versa. So in particular, if we modify alternatingKeysAndValues to
   * eliminate duplicate keys (for buildKeepingLast()) then we have to ensure that a later call to

  }

  /**
   * Generates a decorated collection that remains consistent with the values in the multimap for
   * the provided key. Changes to the multimap may alter the returned collection, and vice versa.
   */
  Collection<V> wrapCollection(@ParametricNullness K key, Collection<V> collection) {
    return new WrappedCollection(key, collection, null);
  }

  final List<V> wrapList(

       *
       * (And I don't believe there's any situation in which we call x.combine(y) when x is a plain
       * ImmutableSet.Builder but y is an ImmutableSortedSet.Builder (or vice versa). Certainly
       * ImmutableSortedSet.Builder.combine() is written as if its argument will never be a plain
       * ImmutableSet.Builder: It casts immediately to ImmutableSortedSet.Builder.)
       */

    return multimap.asMap();
  }

  /**
   * Returns a multimap view of the specified map. The multimap is backed by the map, so changes to
   * the map are reflected in the multimap, and vice versa. If the map is modified while an
   * iteration over one of the multimap's collection views is in progress (except through the
   * iterator's own {@code remove} operation, or through the {@code setValue} operation on a map