* <p>Only for use by a {@link CombiningCallable} or {@link AsyncCombiningCallable} object.
   */
  public static final class Peeker {
    private final ImmutableList<ClosingFuture<?>> futures;
    private volatile boolean beingCalled;

    private Peeker(ImmutableList<ClosingFuture<?>> futures) {
      this.futures = checkNotNull(futures);
    }

    /**
     * Returns the value of {@code closingFuture}.
     *

      List<ReferenceEntry<K, V>> writeOrder) {
    if (map.evictsBySize() || map.expiresAfterAccess()) {
      assertSameEntries(readOrder, ImmutableList.copyOf(segment.accessQueue));
    }
    if (map.expiresAfterWrite()) {
      assertSameEntries(writeOrder, ImmutableList.copyOf(segment.writeQueue));
    }
  }

  private static <K, V> void assertSameEntries(

   * <p>Only for use by a {@link CombiningCallable} or {@link AsyncCombiningCallable} object.
   */
  public static final class Peeker {
    private final ImmutableList<ClosingFuture<?>> futures;
    private volatile boolean beingCalled;

    private Peeker(ImmutableList<ClosingFuture<?>> futures) {
      this.futures = checkNotNull(futures);
    }

    /**
     * Returns the value of {@code closingFuture}.
     *