*     the arguments, or if any has already been {@linkplain #finishToFuture() finished}
   */
  public static Combiner whenAllComplete(
      ClosingFuture<?> future1, ClosingFuture<?>... moreFutures) {
    return whenAllComplete(asList(future1, moreFutures));
  }

  /**
   * Starts specifying how to combine {@link ClosingFuture}s into a single pipeline, assuming they