*/
  public static <V extends @Nullable Object> FluentFuture<V> from(ListenableFuture<V> future) {
    return future instanceof FluentFuture
        ? (FluentFuture<V>) future
        : new ForwardingFluentFuture<V>(future);
  }

  /**
   * Simply returns its argument.
   *
   * @deprecated no need to use this
   * @since 28.0
   */
  @Deprecated