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));

    ms.add(Color.RED);
    assertEquals(0, ms.count(Color.BLUE));
    assertEquals(1, ms.count(Color.YELLOW));
    assertEquals(2, ms.count(Color.RED));
  }

  public void testCollectionCreate() {
    Multiset<Color> ms = EnumMultiset.create(asList(Color.RED, Color.YELLOW, Color.RED));
    assertEquals(0, ms.count(Color.BLUE));
    assertEquals(1, ms.count(Color.YELLOW));
    assertEquals(2, ms.count(Color.RED));
  }

    multiset.add("bar");
    assertEquals(3, multiset.size());
    assertEquals(2, multiset.count("foo"));
  }

  public void testCreateWithSize() {
    Multiset<String> multiset = HashMultiset.create(50);
    multiset.add("foo", 2);
    multiset.add("bar");
    assertEquals(3, multiset.size());
    assertEquals(2, multiset.count("foo"));
  }

  public void testCreateFromIterable() {

    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));

    assertEquals(3, multiset.size());
    assertEquals(2, multiset.count("foo"));
    assertEquals("[foo x 2, bar]", multiset.toString());
  }

  public void testCreateWithSize() {
    Multiset<String> multiset = LinkedHashMultiset.create(50);
    multiset.add("foo", 2);
    multiset.add("bar");
    assertEquals(3, multiset.size());
    assertEquals(2, multiset.count("foo"));
    assertEquals("[foo x 2, bar]", multiset.toString());

    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

  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() {

  public void testElementSetRemovePropagatesToMultiset() {
    Set<E> elementSet = getMultiset().elementSet();
    int size = getNumElements();
    int expectedSize = size - getMultiset().count(e0());
    assertTrue(elementSet.remove(e0()));
    assertFalse(getMultiset().contains(e0()));
    assertEquals(expectedSize, getMultiset().size());
  }

  @CollectionSize.Require(SEVERAL)

    return isEmpty() ? null : getEntry(0);
  }

  @Override
  @CheckForNull
  public Entry<E> lastEntry() {
    return isEmpty() ? null : getEntry(length - 1);
  }

  @Override
  public int count(@CheckForNull Object element) {
    int index = elementSet.indexOf(element);
    return (index >= 0) ? getCount(index) : 0;
  }

  @Override
  public int size() {

      return Multisets.linearTimeSizeImpl(this);
    }

    @Override
    public void clear() {
      throw new UnsupportedOperationException();
    }

    @Override
    public int count(@Nullable Object element) {
      for (Entry<E> entry : entrySet()) {
        if (Objects.equal(entry.getElement(), element)) {
          return entry.getCount();
        }
      }
      return 0;
    }