@Override
    public void increment() {
      getAndIncrement();
    }

    @Override
    public void add(long x) {
      getAndAdd(x);
    }

    @Override
    public long sum() {
      return get();
    }
  }

  private LongAddables() {}

    @Override
    public void increment() {
      getAndIncrement();
    }

    @Override
    public void add(long x) {
      getAndAdd(x);
    }

    @Override
    public long sum() {
      return get();
    }
  }

      assertBitEquals(prev, at.getAndSet(x));
      prev = x;
    }
  }

  /** getAndAdd returns previous value and adds given value */
  public void testGetAndAdd() {
    for (double x : VALUES) {
      for (double y : VALUES) {
        AtomicDouble a = new AtomicDouble(x);
        double z = a.getAndAdd(y);
        assertBitEquals(x, z);
        assertBitEquals(x + y, a.get());
      }
    }
  }

  }

  /**
   * Atomically adds the given value to the current value.
   *
   * @param delta the value to add
   * @return the previous value
   */
  @CanIgnoreReturnValue
  public final double getAndAdd(double delta) {
    while (true) {
      long current = value.get();
      double currentVal = longBitsToDouble(current);
      double nextVal = currentVal + delta;
      long next = doubleToRawLongBits(nextVal);

   *
   * @param i the index
   * @param delta the value to add
   * @return the previous value
   */
  @CanIgnoreReturnValue
  public final double getAndAdd(int i, double delta) {
    while (true) {
      long current = longs.get(i);
      double currentVal = longBitsToDouble(current);
      double nextVal = currentVal + delta;

                      case 4:
                        map.getAndDecrement(key);
                        threadSum--;
                        break;
                      case 5:
                        map.getAndAdd(key, delta);
                        threadSum += delta;
                        break;
                      case 6:
                        long oldValue = map.put(key, delta);

  public FakeTicker setAutoIncrementStep(Duration autoIncrementStep) {
    return setAutoIncrementStep(autoIncrementStep.toNanos(), NANOSECONDS);
  }

  @Override
  public long read() {
    return nanos.getAndAdd(autoIncrementStepNanos);
  }

                      case 4:
                        map.getAndDecrement(key);
                        threadSum--;
                        break;
                      case 5:
                        map.getAndAdd(key, delta);
                        threadSum += delta;
                        break;
                      case 6:
                        long oldValue = map.put(key, delta);

  public FakeTicker setAutoIncrementStep(Duration autoIncrementStep) {
    return setAutoIncrementStep(autoIncrementStep.toNanos(), NANOSECONDS);
  }

  @Override
  public long read() {
    return nanos.getAndAdd(autoIncrementStepNanos);
  }