// for 5.5 seconds happens about 2% of the time.
    boolean longWait = TimeUnit.NANOSECONDS.toSeconds(thread.timeSpentBlocked) >= 5;
    // Count how long it actually took to return; we'll accept any number between the expected delay
    // and the approximate actual delay, to be robust to variance in thread scheduling.
    char overWaitNanosFirstDigit =

          @Override
          public int getCount() {
            Count count = mapEntry.getValue();
            if (count == null || count.get() == 0) {
              Count frequency = backingMap.get(getElement());
              if (frequency != null) {
                return frequency.get();
              }
            }
            return (count == null) ? 0 : count.get();
          }
        };
      }

   * desired count.
   *
   * @param element the element to add or remove occurrences of; may be null only if explicitly
   *     allowed by the implementation
   * @param count the desired count of the element in this multiset
   * @return the count of the element before the operation; possibly zero
   * @throws IllegalArgumentException if {@code count} is negative

    assertThat(twoValuesAccumulator.count()).isEqualTo(2);
    assertThat(twoValuesAccumulatorByAddAllPartitionedPairedStats.count()).isEqualTo(2);
    assertThat(manyValuesAccumulator.count()).isEqualTo(MANY_VALUES_COUNT);
    assertThat(manyValuesAccumulatorByAddAllPartitionedPairedStats.count())
        .isEqualTo(MANY_VALUES_COUNT);
  }

  public void testCountOverflow_doesNotThrow() {

    assertThat(twoValuesAccumulator.count()).isEqualTo(2);
    assertThat(twoValuesAccumulatorByAddAllPartitionedPairedStats.count()).isEqualTo(2);
    assertThat(manyValuesAccumulator.count()).isEqualTo(MANY_VALUES_COUNT);
    assertThat(manyValuesAccumulatorByAddAllPartitionedPairedStats.count())
        .isEqualTo(MANY_VALUES_COUNT);
  }

  public void testCountOverflow_doesNotThrow() {

     * becomes {@code count}.
     *
     * @return the count of {@code element} in the multiset before this call
     * @throws IllegalArgumentException if {@code count} is negative
     */
    @Override
    public int setCount(E element, int count) {
      checkNonnegative(count, "count");

   *
   * <ul>
   *   <li>Both {@code xStats} and {@code yStats} must have the same {@code count}.
   *   <li>If that {@code count} is 1, {@code sumOfProductsOfDeltas} must be exactly 0.0.
   *   <li>If that {@code count} is more than 1, {@code sumOfProductsOfDeltas} must be finite.
   * </ul>
   */
  PairedStats(Stats xStats, Stats yStats, double sumOfProductsOfDeltas) {

    return multiset;
  }

  private HashMultiset() {
    super(new HashMap<E, Count>());
  }

  private HashMultiset(int distinctElements) {
    super(Maps.<E, Count>newHashMapWithExpectedSize(distinctElements));
  }

  /**
   * @serialData the number of distinct elements, the first element, its count, the second element,
   *     its count, and so on
   */
  @GwtIncompatible // java.io.ObjectOutputStream
  @J2ktIncompatible

            V entryValue = e.getValue();

            if (entryValue == null) {
              ++modCount;
              setValue(e, value);
              newCount = this.count; // count remains unchanged
              this.count = newCount; // write-volatile
              return null;
            } else if (onlyIfAbsent) {
              // Mimic
              // "if (!map.containsKey(key)) ...

  private static <E extends @Nullable Object> Entry<E> entry(final E element, final int count) {
    return Multisets.immutableEntry(element, count);
  }

  private static <E extends @Nullable Object> Entry<E> control(E element, int count) {
    return HashMultiset.create(Collections.nCopies(count, element)).entrySet().iterator().next();
  }

  public void testToString() {