size += other.size;
      return this;
    }

    /**
     * Returns a newly-created immutable sorted map.
     *
     * <p>Prefer the equivalent method {@link #buildOrThrow()} to make it explicit that the method
     * will throw an exception if there are duplicate keys. The {@code build()} method will soon be
     * deprecated.
     *

   *
   * @since 20.0 (varargs overload since 2.0)
   */
  public static void checkArgument(
      boolean expression,
      // TODO: cl/604933487 - Make errorMessageTemplate consistently @CheckForNull across overloads.
      @CheckForNull String errorMessageTemplate,
      @CheckForNull Object p1,
      @CheckForNull Object p2) {
    if (!expression) {

  // Timed Get
  // There are a few design constraints to consider
  // * We want to be responsive to small timeouts, unpark() has non trivial latency overheads (I
  //   have observed 12 micros on 64-bit linux systems to wake up a parked thread). So if the
  //   timeout is small we shouldn't park(). This needs to be traded off with the cpu overhead of
  //   spinning, so we use SPIN_THRESHOLD_NANOS which is what AbstractQueuedSynchronizer uses for

 * API</h2>
 *
 * <p>The successor to Guava's caching API is <a
 * href="https://github.com/ben-manes/caffeine/wiki">Caffeine</a>. Its API is designed to make it a
 * nearly drop-in replacement. It requires Java 8+, and is not available for Android or GWT/J2CL,
 * and may have <a href="https://github.com/ben-manes/caffeine/wiki/Guava">different (usually

    CacheTesting.simulateKeyReclamation(cache, key);
    cache.refresh(key);
    checkNothingLogged();
    assertEquals(3, countingLoader.getCount());
  }

  /**
   * Make sure LoadingCache correctly wraps ExecutionExceptions and UncheckedExecutionExceptions.
   */
  public void testLoadingExceptionWithCause() {
    final Exception cause = new Exception();

      super.combine(other);
      return this;
    }

    /**
     * Returns a newly-created immutable sorted map.
     *
     * <p>Prefer the equivalent method {@link #buildOrThrow()} to make it explicit that the method
     * will throw an exception if there are duplicate keys. The {@code build()} method will soon be
     * deprecated.
     *

    CacheTesting.simulateKeyReclamation(cache, key);
    cache.refresh(key);
    checkNothingLogged();
    assertEquals(3, countingLoader.getCount());
  }

  /**
   * Make sure LoadingCache correctly wraps ExecutionExceptions and UncheckedExecutionExceptions.
   */
  public void testLoadingExceptionWithCause() {
    final Exception cause = new Exception();

        .that(bucketsOf(map1))
        .isEqualTo(initialBuckets);

    /*
     * Something slightly different happens when the entries are added all at
     * once; make sure that passes too.
     */
    map2.putAll(map1);
    assertWithMessage("table size after adding " + size + " elements")
        .that(bucketsOf(map1))
        .isEqualTo(initialBuckets);

        .that(bucketsOf(map1))
        .isEqualTo(initialBuckets);

    /*
     * Something slightly different happens when the entries are added all at
     * once; make sure that passes too.
     */
    map2.putAll(map1);
    assertWithMessage("table size after adding " + size + " elements")
        .that(bucketsOf(map1))
        .isEqualTo(initialBuckets);

  //    assigned prior to calling addListener, and addListener happens-before any invocation of the
  //    listener. Notably, this means that 'volatile' is unnecessary to make 'inputFuture' visible
  //    to the listener.
  //
  // 2. In done() where we may propagate cancellation to the input. In this case it is _not_ fine.