}

  /**
   * Configures the given map maker to use weak keys, if possible; does nothing otherwise (i.e., in
   * GWT). This is sometimes acceptable, when only server-side code could generate enough volume
   * that reclamation becomes important.
   */
  @J2ktIncompatible
  static MapMaker tryWeakKeys(MapMaker mapMaker) {
    return mapMaker.weakKeys();
  }

        NullPointerException.class, () -> multimap().putAll(k3(), newArrayList(null, v3())));

    /*
     * In principle, a Multimap implementation could add e3 first before failing on the null. But
     * that seems unlikely enough to be worth complicating the test over, especially if there's any
     * chance that a permissive test could mask a bug.
     */
    expectUnchanged();

      Thread.interrupted();
    }
  }

  /**
   * awaitFullGc() is not quite as reliable a way to ensure calling of a specific finalize method as
   * the more direct await* methods, but should be reliable enough in practice to avoid flakiness of
   * this test. (And if it isn't, we'd like to know about it first!)
   */
  public void testAwaitFullGc() {
    CountDownLatch finalizerRan = new CountDownLatch(1);

  }

  /**
   * Configures the given map maker to use weak keys, if possible; does nothing otherwise (i.e., in
   * GWT). This is sometimes acceptable, when only server-side code could generate enough volume
   * that reclamation becomes important.
   */
  @J2ktIncompatible
  static MapMaker tryWeakKeys(MapMaker mapMaker) {
    return mapMaker.weakKeys();
  }

    tests themselves and not the code being tested that needs that access, though there's no
    obvious way to ensure that.

    We could consider arranging things so that only the tests we know need this would get
    the add-opens. Right now that doesn't seem worth the effort, though.
    -->
    <test.add.opens>
      --add-opens java.base/java.lang=ALL-UNNAMED

    tests themselves and not the code being tested that needs that access, though there's no
    obvious way to ensure that.

    We could consider arranging things so that only the tests we know need this would get
    the add-opens. Right now that doesn't seem worth the effort, though.
    -->
    <test.add.opens>
      --add-opens java.base/java.lang=ALL-UNNAMED

    long timeoutNanos = unit.toNanos(timeout);
    if (timeoutNanos <= OverflowAvoidingLockSupport.MAX_NANOSECONDS_THRESHOLD) {
      return super.get(timeout, unit);
    }
    // Waiting 68 years should be enough for any program.
    return super.get(
        min(timeoutNanos, OverflowAvoidingLockSupport.MAX_NANOSECONDS_THRESHOLD), NANOSECONDS);
  }

  /** Internal implementation detail used to invoke the listeners. */

              }
            },
            directExecutor()));
    thingToCancel[0] = serializer.submit(Callables.returning(null), directExecutor());
    results.add(thingToCancel[0]);
    // Enqueue more than enough tasks to force reentrancy.
    for (int i = 0; i < 5; i++) {
      results.add(serializer.submit(Callables.returning(null), directExecutor()));
    }

    manualExecutorTask[0].run();

         * I'm not sure that we could actually get here for *Android*: I would expect us to enter
         * the POSIX code path instead. And if we tried this code path, we'd have trouble unless we
         * were running under a new enough version of Android to support NIO.
         *
         * So this is probably just the "Windows Java 8" case. In that case, if we wanted *another*
         * layer of fallback before consulting the system property, we could try

    expected.addAll(index, elements);
    expectContents(expected);
  }

  /*
   * TODO: if we're testing a list, we could check indexOf(). (Doing it in
   * AbstractListTester isn't enough because many tests that run on lists don't
   * extends AbstractListTester.) We could also iterate over all elements to
   * verify absence
   */
  protected void expectMissing(E... elements) {