* A mutable value of type {@code int}, for multisets to use in tracking counts of values.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
final class Count implements Serializable {
  private int value;

  Count(int value) {
    this.value = value;
  }

  public int get() {
    return value;
  }

  public void add(int delta) {
    value += delta;
  }

    assertThat(manyValuesAccumulatorByAddAllIterable.count()).isEqualTo(MANY_VALUES_COUNT);
    assertThat(manyValuesAccumulatorByAddAllIterator.count()).isEqualTo(MANY_VALUES_COUNT);
    assertThat(manyValuesAccumulatorByAddAllVarargs.count()).isEqualTo(MANY_VALUES_COUNT);
    assertThat(manyValuesAccumulatorByRepeatedAdd.count()).isEqualTo(MANY_VALUES_COUNT);

    assertThat(MANY_VALUES_STATS_SNAPSHOT.count()).isEqualTo(MANY_VALUES_COUNT);
    assertThat(INTEGER_MANY_VALUES_STATS_VARARGS.count()).isEqualTo(INTEGER_MANY_VALUES_COUNT);
    assertThat(INTEGER_MANY_VALUES_STATS_ITERABLE.count()).isEqualTo(INTEGER_MANY_VALUES_COUNT);
    assertThat(LONG_MANY_VALUES_STATS_ITERATOR.count()).isEqualTo(LONG_MANY_VALUES_COUNT);

      implements Serializable {
    @ParametricNullness private final E element;
    private final int count;

    ImmutableEntry(@ParametricNullness E element, int count) {
      this.element = element;
      this.count = count;
      checkNonnegative(count, "count");
    }

    @Override
    @ParametricNullness
    public final E getElement() {
      return element;
    }

  @Override
  public int setCount(@ParametricNullness E element, int count) {
    checkNonnegative(count, "count");
    if (!range.contains(element)) {
      checkArgument(count == 0);
      return 0;
    }

    AvlNode<E> root = rootReference.get();
    if (root == null) {
      if (count > 0) {
        add(element, count);
      }
      return 0;
    }

    // no entry
    assertEquals(0, segment.count);
    assertNull(segment.remove(key, hash));
    assertEquals(0, segment.count);

    // same key
    segment.setTableEntryForTesting(index, entry);
    segment.count++;
    assertEquals(1, segment.count);
    assertSame(oldValue, segment.get(key, hash));
    assertSame(oldValue, segment.remove(key, hash));
    assertEquals(0, segment.count);
    assertNull(segment.get(key, hash));

    // no entry
    assertEquals(0, segment.count);
    assertNull(segment.remove(key, hash));
    assertEquals(0, segment.count);

    // same key
    segment.setTableEntryForTesting(index, entry);
    segment.count++;
    assertEquals(1, segment.count);
    assertSame(oldValue, segment.get(key, hash));
    assertSame(oldValue, segment.remove(key, hash));
    assertEquals(0, segment.count);
    assertNull(segment.get(key, hash));

  public void testAddOccurrences() {
    int originalCount = getMultiset().count(e0());
    assertEquals("old count", originalCount, getMultiset().add(e0(), 2));
    assertEquals("old count", originalCount + 2, getMultiset().count(e0()));
  }

  @CollectionFeature.Require(SUPPORTS_ADD)
  public void testAddSeveralTimes() {
    int originalCount = getMultiset().count(e0());
    assertEquals(originalCount, getMultiset().add(e0(), 2));

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

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

  /**
   * A sensible definition of {@link #contains} in terms of {@link #count}. If you override {@link

    int originalCount = getMultiset().count(e0());
    assertEquals("old count", originalCount, getMultiset().remove(e0(), 0));
    expectUnchanged();
  }

  @CollectionSize.Require(absent = ZERO)
  @CollectionFeature.Require(SUPPORTS_REMOVE)
  public void testRemove_occurrences_present() {
    assertEquals(
        "multiset.remove(present, 2) didn't return the old count",
        1,
        getMultiset().remove(e0(), 2));