Cache<Object, Object> cache =
        CacheBuilder.newBuilder().removalListener(removalListener).build();
    cache.put("a", "b");
    cache.asMap().computeIfAbsent("a", k -> "c");
    assertTrue(notifications.toString(), notifications.isEmpty());
  }

  public void testCopyEntry_computing() {
    final CountDownLatch startSignal = new CountDownLatch(1);
    final CountDownLatch computingSignal = new CountDownLatch(1);

      StringBuilder builder = new StringBuilder();
      for (StackTraceElement trace : thread.getStackTrace()) {
        builder.append("\tat ").append(trace).append('\n');
      }
      fail(builder.toString());
    }
  }

  /**
   * Returns an iterable containing all combinations of maximumSize, expireAfterAccess/Write,
   * weakKeys and weak/softValues.
   */