Logger.getLogger(AggregateFuture.class.getName());
  private final TestLogHandler aggregateFutureLogHandler = new TestLogHandler();

  private static final String DATA1 = "data";
  private static final String DATA2 = "more data";
  private static final String DATA3 = "most data";

  @Override
  public void setUp() throws Exception {
    super.setUp();
    aggregateFutureLogger.addHandler(aggregateFutureLogHandler);
  }

      Logger.getLogger(AggregateFuture.class.getName());
  private final TestLogHandler aggregateFutureLogHandler = new TestLogHandler();

  private static final String DATA1 = "data";
  private static final String DATA2 = "more data";
  private static final String DATA3 = "most data";

  @Override
  public void setUp() throws Exception {
    super.setUp();
    aggregateFutureLogger.addHandler(aggregateFutureLogHandler);
  }

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
use in saying anything more till the Pigeon had finished.

  `As if it wasn't trouble enough hatching the eggs,' said the
Pigeon; `but I must be on the look-out for serpents night and

  static class Segment<K, V> extends ReentrantLock {

    /*
     * TODO(fry): Consider copying variables (like evictsBySize) from outer class into this class.
     * It will require more memory but will reduce indirection.
     */

    /*
     * Segments maintain a table of entry lists that are ALWAYS kept in a consistent state, so can

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
use in saying anything more till the Pigeon had finished.

  `As if it wasn't trouble enough hatching the eggs,' said the
Pigeon; `but I must be on the look-out for serpents night and

 *
 * <ol>
 *   <li>A pipeline starts at its leaf step (or steps), which is created from either a callable
 *       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

   * the first appearance of each key in {@code keys}.
   *
   * <p>When there are multiple instances of a key in {@code keys}, it is unspecified whether {@code
   * valueFunction} will be applied to more than one instance of that key and, if it is, which
   * result will be mapped to that key in the returned map.
   *
   * <p>If {@code keys} is a {@link Set}, a live view can be obtained instead of a copy using {@link

   * the first appearance of each key in {@code keys}.
   *
   * <p>When there are multiple instances of a key in {@code keys}, it is unspecified whether {@code
   * valueFunction} will be applied to more than one instance of that key and, if it is, which
   * result will be mapped to that key in the returned map.
   *
   * <p>If {@code keys} is a {@link Set}, a live view can be obtained instead of a copy using {@link

 *
 * <ol>
 *   <li>A pipeline starts at its leaf step (or steps), which is created from either a callable
 *       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

  static class Segment<K, V> extends ReentrantLock {

    /*
     * TODO(fry): Consider copying variables (like evictsBySize) from outer class into this class.
     * It will require more memory but will reduce indirection.
     */

    /*
     * Segments maintain a table of entry lists that are ALWAYS kept in a consistent state, so can