*
 * ### Path
 *
 * The path identifies a specific resource on the host. Paths have a hierarchical structure like
 * "/square/okhttp/issues/1486" and decompose into a list of segments like `["square", "okhttp",
 * "issues", "1486"]`.
 *
 * This class offers methods to compose and decompose paths by segment. It composes each path
 * from a list of segments by alternating between "/" and the encoded segment. For example the

   *     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(
          ListenableFuture<I> input, Function<? super I, ? extends O> function, Executor executor) {