*     the returned future.
   * @param executor Executor to run the function in.
   * @return A future that holds result of the transformation.
   * @since 9.0 (in 2.0 as {@code compose})
   */
  public static <I extends @Nullable Object, O extends @Nullable Object>
      ListenableFuture<O> transform(

   *     the returned future.
   * @param executor Executor to run the function in.
   * @return A future that holds result of the transformation.
   * @since 9.0 (in 2.0 as {@code compose})
   */
  public static <I extends @Nullable Object, O extends @Nullable Object>
      ListenableFuture<O> transform(

  }

  /**
   * Returns a view of a multimap whose values are derived from the original multimap's entries. In
   * contrast to {@link #transformValues}, this method's entry-transformation logic may depend on
   * the key as well as the value.
   *
   * <p>All other properties of the transformed multimap, such as iteration order, are left intact.
   * For example, the code:
   *