assertThat(striped.getAt(i)).isSameInstanceAs(object); // idempotent
      observed.add(object);
    }
    assertTrue("All stripes observed", observed.size() == striped.size());

    // this uses #get(key), makes sure an already observed stripe is returned
    for (int i = 0; i < striped.size() * 100; i++) {
      assertTrue(observed.contains(striped.get(new Object())));
    }

    try {
      striped.getAt(-1);

      assertThat(striped.getAt(i)).isSameInstanceAs(object); // idempotent
      observed.add(object);
    }
    assertTrue("All stripes observed", observed.size() == striped.size());

    // this uses #get(key), makes sure an already observed stripe is returned
    for (int i = 0; i < striped.size() * 100; i++) {
      assertTrue(observed.contains(striped.get(new Object())));
    }

    try {
      striped.getAt(-1);

        int falseCount = 0;
        for (int i = 0; i < readerThreadCount; i++) {
            for (Boolean observed : observations[i]) {
                if (!observed) {
                    falseCount++;
                }
            }
        }
        assertTrue("Some threads should have observed alive=false", falseCount > 0);
    }

    /**

            }
          };
      executor.execute(errorTask);
      service.execute(barrierTask); // submit directly to the service
      // the barrier task runs after the error task so we know that the error has been observed by
      // SequentialExecutor by the time the barrier is satisfied
      barrier.await(1, SECONDS);
      executor.execute(barrierTask);
      // timeout means the second task wasn't even tried

            }
          };
      executor.execute(errorTask);
      service.execute(barrierTask); // submit directly to the service
      // the barrier task runs after the error task so we know that the error has been observed by
      // SequentialExecutor by the time the barrier is satisfied
      barrier.await(1, SECONDS);
      executor.execute(barrierTask);
      // timeout means the second task wasn't even tried

   * happens when an {@link AtomicInteger#compareAndSet} fails, but we can simulate the case where
   * the putIfAbsent returns a non-null value, and the case where the replace() of an observed zero
   * fails.
   */
  public void testAdd_withFailures() {
    AtomicInteger existing = new AtomicInteger(12);
    AtomicInteger existingZero = new AtomicInteger(0);

    // initial map.get()

      }

      return value;
    }

    /**
     * Performs routine cleanup following a read. Normally cleanup happens during writes, or from
     * the cleanupExecutor. If cleanup is not observed after a sufficient number of reads, try
     * cleaning up from the read thread.
     */
    void postReadCleanup() {
      if ((readCount.incrementAndGet() & DRAIN_THRESHOLD) == 0) {
        runCleanup();

      }

      return value;
    }

    /**
     * Performs routine cleanup following a read. Normally cleanup happens during writes, or from
     * the cleanupExecutor. If cleanup is not observed after a sufficient number of reads, try
     * cleaning up from the read thread.
     */
    void postReadCleanup() {
      if ((readCount.incrementAndGet() & DRAIN_THRESHOLD) == 0) {
        runCleanup();

 *   <dt>An IPv6 "IPv4 mapped" address, {@code "::ffff:192.168.0.1"}.
 *   <dd>{@code 00 00 00 00 00 00 00 00 00 00 ff ff c0 a8 00 01}
 * </dl>
 *
 * <p>A few notes about IPv6 "IPv4 mapped" addresses and their observed use in Java.
 *
 * <p>"IPv4 mapped" addresses were originally a representation of IPv4 addresses for use on an IPv6
 * socket that could receive both IPv4 and IPv6 connections (by disabling the {@code IPV6_V6ONLY}

  //    (hypothetical) unsafe read by our caller. Note: adding 'volatile' does not fix this issue,
  //    it would just add an edge such that if done() observed non-null, then it would also
  //    definitely observe all earlier writes, but we still have no guarantee that done() would see
  //    the initial write (just stronger guarantees if it does).
  //