V put(@ParametricNullness K key, @ParametricNullness V value, boolean force) {
    int keyHash = Hashing.smearedHash(key);
    int entryForKey = findEntryByKey(key, keyHash);
    if (entryForKey != ABSENT) {
      V oldValue = values[entryForKey];
      if (Objects.equal(oldValue, value)) {
        return value;
      } else {
        replaceValueInEntry(entryForKey, value, force);
        return oldValue;
      }
    }

  public V put(@ParametricNullness K key, @ParametricNullness V value) {
    return put(key, value, false);
  }

  @CheckForNull
  private V put(@ParametricNullness K key, @ParametricNullness V value, boolean force) {
    int keyHash = smearedHash(key);
    int valueHash = smearedHash(value);

    BiEntry<K, V> oldEntryForKey = seekByKey(key, keyHash);
    if (oldEntryForKey != null

        return ImmutableMap.builder()
            .putAll(Lists.transform(keys, k -> Maps.immutableEntry(k, "dummy value")))
            .buildOrThrow();
      }
    },
    FORCE_JDK {
      @Override
      public Map<Object, Object> create(List<?> keys) {
        ImmutableMap.Builder<Object, Object> builder = ImmutableMap.builder();
        for (Object k : keys) {

 * strategies.
 *
 * <ul>
 *   <li>SafeAtomicHelper: uses Atomic FieldsUpdaters to implement synchronization
 *   <li>SynchronizedHelper: uses {@code synchronized} blocks for synchronization
 * </ul>
 *
 * To force selection of our fallback strategies we load {@link AggregateFutureState} (and all of
 * {@code com.google.common.util.concurrent}) in degenerate class loaders which make certain

  public void testAddAllAtIndex_nullSupported() {
    List<E> containsNull = singletonList(null);
    assertTrue("addAll(n, containsNull) should return true", getList().addAll(0, containsNull));
    /*
     * We need (E) to force interpretation of null as the single element of a
     * varargs array, not the array itself
     */
    expectAdded(0, (E) null);
  }

  @ListFeature.Require(SUPPORTS_ADD_WITH_INDEX)

  public void testAddAll_nullSupported() {
    List<E> containsNull = singletonList(null);
    assertTrue("addAll(containsNull) should return true", collection.addAll(containsNull));
    /*
     * We need (E) to force interpretation of null as the single element of a
     * varargs array, not the array itself
     */
    expectAdded((E) null);
  }

  @CollectionFeature.Require(value = SUPPORTS_ADD, absent = ALLOWS_NULL_VALUES)

      ImmutableDoubleArray.builder(-1);
      fail();
    } catch (IllegalArgumentException expected) {
    }
  }

  /**
   * If there's a bug in builder growth, we wouldn't know how to expose it. So, brute force the hell
   * out of it for a while and see what happens.
   */
  public void testBuilder_bruteForce() {
    for (int i = 0; i < reduceIterationsIfGwt(100); i++) {

      ImmutableLongArray.builder(-1);
      fail();
    } catch (IllegalArgumentException expected) {
    }
  }

  /**
   * If there's a bug in builder growth, we wouldn't know how to expose it. So, brute force the hell
   * out of it for a while and see what happens.
   */
  public void testBuilder_bruteForce() {
    for (int i = 0; i < reduceIterationsIfGwt(100); i++) {

              // 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
              // expected false positive probability goes up!
              assertThat(bloomFilter.expectedFpp()).isLessThan(safetyFalsePositiveRate);

 * </ul>
 *
 * <p>Disadvantages compared to {@code int[]}:
 *
 * <ul>
 *   <li>Memory footprint has a fixed overhead (about 24 bytes per instance).
 *   <li><i>Some</i> construction use cases force the data to be copied (though several construction
 *       APIs are offered that don't).
 *   <li>Can't be passed directly to methods that expect {@code int[]} (though the most common
 *       utilities do have replacements here).