subdued tone, and added with a kind of sob, `I've tried every
way, and nothing seems to suit them!'

  `I haven't the least idea what you're talking about,' said
Alice.

  `I've tried the roots of trees, and I've tried banks, and I've
tried hedges,' the Pigeon went on, without attending to her; `but
those serpents!  There's no pleasing them!'

  Alice was more and more puzzled, but she thought there was no

       */
      SettableFuture<Object> root = SettableFuture.create();
      ListenableFuture<Object> unused = transform(root, identity(), directExecutor());
      root.set("foo");
    }

    SettableFuture<Object> root = SettableFuture.create();
    ListenableFuture<Object> output = root;
    for (int i = 0; i < 10000; i++) {

subdued tone, and added with a kind of sob, `I've tried every
way, and nothing seems to suit them!'

  `I haven't the least idea what you're talking about,' said
Alice.

  `I've tried the roots of trees, and I've tried banks, and I've
tried hedges,' the Pigeon went on, without attending to her; `but
those serpents!  There's no pleasing them!'

  Alice was more and more puzzled, but she thought there was no

 *       block or a {@link ListenableFuture}.
 *   <li>Each other step is derived from one or more input steps. At each step, zero or more objects
 *       can be captured for later closing.
 *   <li>There is one last step (the root of the tree), from which you can extract the final result
 *       of the computation. After that result is available (or the computation fails), all objects
 *       captured by any of the steps in the pipeline are closed.
 * </ol>