}

  public void testBuilderSetCount() {
    ImmutableMultiset<String> multiset =
        new ImmutableMultiset.Builder<String>().add("a").setCount("a", 2).setCount("b", 3).build();
    assertEquals(HashMultiset.create(asList("a", "a", "b", "b", "b")), multiset);
  }

  public void testBuilderAddHandlesNullsCorrectly() {

              multiset.add(key, delta);
              deltas[keyIndex] += delta;
              break;
            }
          case SET_COUNT:
            {
              int newValue = random.nextInt(3);
              int oldValue = multiset.setCount(key, newValue);
              deltas[keyIndex] += (newValue - oldValue);
              break;
            }
          case SET_COUNT_IF:
            {

  }

  public void testBuilderSetCount() {
    ImmutableMultiset<String> multiset =
        new ImmutableMultiset.Builder<String>().add("a").setCount("a", 2).setCount("b", 3).build();
    assertEquals(HashMultiset.create(asList("a", "a", "b", "b", "b")), multiset);
  }

  public void testBuilderAddHandlesNullsCorrectly() {

  }

  public void testBuilderSetCount() {
    ImmutableSortedMultiset<String> multiset =
        ImmutableSortedMultiset.<String>naturalOrder()
            .add("a")
            .setCount("a", 2)
            .setCount("b", 3)
            .build();
    assertEquals(HashMultiset.create(asList("a", "a", "b", "b", "b")), multiset);
  }

  public void testBuilderAddHandlesNullsCorrectly() {

   *
   * @return the count of {@code element} in the multiset before this call
   * @throws IllegalArgumentException if {@code count} is negative
   */
  @CanIgnoreReturnValue
  @Override
  public int setCount(E element, int count) {
    checkNotNull(element);
    checkNonnegative(count, "count");
    while (true) {
      AtomicInteger existingCounter = safeGet(countMap, element);
      if (existingCounter == null) {

    }

    frequency.add(-numberRemoved);
    size -= numberRemoved;
    return oldCount;
  }

  // Roughly a 33% performance improvement over AbstractMultiset.setCount().
  @CanIgnoreReturnValue
  @Override
  public int setCount(@ParametricNullness E element, int count) {
    checkNonnegative(count, "count");

    Count existingCounter;
    int oldCount;
    if (count == 0) {

    assertEquals(0, multiset.remove(entry.getElement(), entry.getCount()));
    assertFalse(multiset.remove(entry.getElement()));
    assertFalse(multiset.elementSet().remove(entry.getElement()));
  }

  void expectSetCountFailure(SortedMultiset<E> multiset, Entry<E> entry) {
    try {
      multiset.setCount(entry.getElement(), multiset.count(entry.getElement()));

    assertEquals(0, multiset.remove(entry.getElement(), entry.getCount()));
    assertFalse(multiset.remove(entry.getElement()));
    assertFalse(multiset.elementSet().remove(entry.getElement()));
  }

  void expectSetCountFailure(SortedMultiset<E> multiset, Entry<E> entry) {
    try {
      multiset.setCount(entry.getElement(), multiset.count(entry.getElement()));

      }
    }

    @Override
    public int setCount(@ParametricNullness E element, int count) {
      synchronized (mutex) {
        return delegate().setCount(element, count);
      }
    }

    @Override
    public boolean setCount(@ParametricNullness E element, int oldCount, int newCount) {
      synchronized (mutex) {
        return delegate().setCount(element, oldCount, newCount);
      }
    }

      }
    }

    @Override
    public int setCount(@ParametricNullness E element, int count) {
      synchronized (mutex) {
        return delegate().setCount(element, count);
      }
    }

    @Override
    public boolean setCount(@ParametricNullness E element, int oldCount, int newCount) {
      synchronized (mutex) {
        return delegate().setCount(element, oldCount, newCount);
      }
    }