}
    }
  }

  /** accumulateAndGet with sum adds given value to current, and returns current value */
  public void testAccumulateAndGetWithSum() {
    AtomicDoubleArray aa = new AtomicDoubleArray(SIZE);
    for (int i : new int[] {0, SIZE - 1}) {
      for (double x : VALUES) {
        for (double y : VALUES) {
          aa.set(i, x);
          double z = aa.accumulateAndGet(i, y, Double::sum);

  /**
   * Adds {@code delta} to the value currently associated with {@code key}, and returns the new
   * value.
   */
  @CanIgnoreReturnValue
  public long addAndGet(K key, long delta) {
    return accumulateAndGet(key, delta, Long::sum);
  }

  /**
   * Increments by one the value currently associated with {@code key}, and returns the old value.
   */
  @CanIgnoreReturnValue
  public long getAndIncrement(K key) {