}

  /**
   * Returns a hash table for the specified keys and values, and ensures that neither keys nor
   * values are null. This method may update {@code alternatingKeysAndValues} if there are duplicate
   * keys. If so, the return value will indicate how many entries are still valid, and will also

    RateLimiter rateLimiter = RateLimiter.create(1.0, stopwatch);
    rateLimiter.acquire(1); // no wait
    rateLimiter.acquire(1); // R1.00, to repay previous

    rateLimiter.setRate(2.0); // update the rate!

    rateLimiter.acquire(1); // R1.00, to repay previous (the previous was under the old rate!)
    rateLimiter.acquire(2); // R0.50, to repay previous (now the rate takes effect)

       * one as it is because one of our users has defined a wrapper API around Preconditions,
       * declaring a checkState method that accepts a possibly null template. So we'd need to update
       * that user first.
       */
      @CheckForNull String errorMessageTemplate,
      @CheckForNull @Nullable Object... errorMessageArgs) {
    if (!expression) {

  static final int CONTAINS_VALUE_RETRIES = 3;

  /**
   * Number of cache access operations that can be buffered per segment before the cache's recency
   * ordering information is updated. This is used to avoid lock contention by recording a memento
   * of reads and delaying a lock acquisition until the threshold is crossed or a mutation occurs.
   *
   * <p>This must be a (2^n)-1 as it is used as a mask.

   */
  public final boolean compareAndSet(int i, double expect, double update) {
    return longs.compareAndSet(i, doubleToRawLongBits(expect), doubleToRawLongBits(update));
  }

  /**
   * Atomically sets the element at position {@code i} to the given updated value if the current
   * value is <a href="#bitEquals">bitwise equal</a> to the expected value.
   *
   * <p>May <a

    // let computation complete
    letGetFinishSignal.countDown();
    getFinishedSignal.await();
    checkNothingLogged();

    // asMap view should have been updated
    assertEquals(2, cache.size());
    assertEquals(getKey + suffix, map.get(getKey));
    assertEquals(refreshKey + suffix, map.get(refreshKey));
  }

   * {@code factory}, and the multimap contents are all serializable.
   *
   * <p>The multimap is not threadsafe when any concurrent operations update the multimap, even if
   * {@code map} and the instances generated by {@code factory} are. Concurrent read operations will
   * work correctly. To allow concurrent update operations, wrap the multimap with a call to {@link
   * #synchronizedMultimap}.
   *

    // Memoized get also retains the value.
    assertEquals(6, getDoneFromTimeoutOverload(transformedFuture).intValue());

    // Unsurprisingly, recomposing the future will return an updated value.
    assertEquals(8, getDone(transform(immediateFuture, adder, directExecutor())).intValue());

    // Repeating, with the timeout version
    assertEquals(
        8,

    // we really just want to wait for the thread to be in the failure callback so we wait for that
    // explicitly instead.
    failEnter.await();
    assertFalse("State should be updated before calling listeners", manager.isHealthy());
    // now we want to stop the services.
    Thread stoppingThread =
        new Thread() {
          @Override
          public void run() {

        // may have scheduled more operations on another thread, and if those operations then
        // trigger reentrant calls that thread will have updated the latestTaskQueue field, and
        // we'd be interfering with their operation.
        executingTaskQueue.thread = null;
      }
    }

    private boolean trySetStarted() {