*
     * - Under Java 9+, createTempDir() succeeds because it can look up the *real* username, rather
     * than relying on the one from the system property.
     *
     * - Under Java 8, createTempDir() fails because it falls back to the bogus username from the
     * system property.
     */

    String save = System.getProperty("user.name");

    assertThat(keySet).containsExactly(1, 3, 6, 8);

    // get fails to save 1, put saves 3
    cache.asMap().put(3, -3);
    getAll(cache, asList(1));
    CacheTesting.drainRecencyQueues(cache);
    ticker.advance(1, MILLISECONDS);
    assertThat(keySet).containsExactly(6, 8, 3);

    // get(K, Callable) fails to save 8, replace saves 6
    cache.asMap().replace(6, -6);

  }

  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
  public void testRemove_occurrences_unsupported_absent() {
    // notice: we don't care whether it succeeds, or fails with UOE
    try {
      assertEquals(
          "multiset.remove(absent, 2) didn't return 0 or throw an exception",
          0,
          getMultiset().remove(e3(), 2));

    initCollectionWithNullElement();
    expectReturnsTrue(disjoint);
    expectContents();
  }

  // retainAll(null)

  /*
   * AbstractCollection fails the retainAll(null) test when the subject
   * collection is empty, but we'd still like to test retainAll(null) when we
   * can. We split the test into empty and non-empty cases. This allows us to
   * suppress only the former.

      assertBitEquals(VALUES[i], aa.get(i));
      aa.lazySet(i, -3.0);
      assertBitEquals(-3.0, aa.get(i));
    }
  }

  /** compareAndSet succeeds in changing value if equal to expected else fails */
  public void testCompareAndSet() {
    AtomicDoubleArray aa = new AtomicDoubleArray(SIZE);
    for (int i : new int[] {0, SIZE - 1}) {
      double prev = 0.0;
      double unused = Math.E + Math.PI;

  /**
   * This counter prevents an ABA issue where a thread may successfully schedule the worker, the
   * worker runs and exhausts the queue, another thread enqueues a task and fails to schedule the
   * worker, and then the first thread's call to delegate.execute() returns. Without this counter,
   * it would observe the QUEUING state and set it to QUEUED, and the worker would never be

   * previously cached values. This method will throw an exception if {@link CacheLoader#loadAll}
   * returns {@code null}, returns a map containing null keys or values, or fails to return an entry
   * for each requested key.
   *
   * <p>Note that duplicate elements in {@code keys}, as determined by {@link Object#equals}, will
   * be ignored.
   *

      assertBitEquals(VALUES[i], aa.get(i));
      aa.lazySet(i, -3.0);
      assertBitEquals(-3.0, aa.get(i));
    }
  }

  /** compareAndSet succeeds in changing value if equal to expected else fails */
  public void testCompareAndSet() {
    AtomicDoubleArray aa = new AtomicDoubleArray(SIZE);
    for (int i : new int[] {0, SIZE - 1}) {
      double prev = 0.0;
      double unused = Math.E + Math.PI;

  /**
   * Ensures the truth of an expression involving one or more parameters to the calling method.
   *
   * @param expression a boolean expression
   * @param errorMessage the exception message to use if the check fails; will be converted to a
   *     string using {@link String#valueOf(Object)}
   * @throws IllegalArgumentException if {@code expression} is false
   */

              // positive).
              bloomFilter.put(key);
              // False negative should *never* happen.
              assertThat(bloomFilter.mightContain(key)).isTrue();

              // If this check ever fails, that means we need to either bump the
              // number of expected insertions or don't run the test for so long.
              // Don't forget, the bloom filter slowly saturates over time and the