@CollectionSize.Require(absent = {ZERO, ONE})
  public void testLastIndexOf_duplicate() {
    E[] array = createSamplesArray();
    array[getNumElements() / 2] = e0();
    collection = getSubjectGenerator().create(array);
    assertEquals(
        "lastIndexOf(duplicate) should return index of last occurrence",
        getNumElements() / 2,
        getList().lastIndexOf(e0()));
  }

    array[getNullLocation()] = null;
    return array;
  }

  protected void initCollectionWithNullElement() {
    E[] array = createArrayWithNullElement();
    resetContainer(getSubjectGenerator().create(array));
  }

  /**
   * Equivalent to {@link #expectMissing(Object[]) expectMissing}{@code (null)} except that the call
   * to {@code contains(null)} is permitted to throw a {@code NullPointerException}.

    array[getNullLocation()] = null;
    return array;
  }

  protected void initCollectionWithNullElement() {
    E[] array = createArrayWithNullElement();
    resetContainer(getSubjectGenerator().create(array));
  }

  /**
   * Equivalent to {@link #expectMissing(Object[]) expectMissing}{@code (null)} except that the call
   * to {@code contains(null)} is permitted to throw a {@code NullPointerException}.

  @Override
  public void setUp() throws Exception {
    super.setUp();
    navigableMap = (NavigableMap<K, V>) getMap();
    entries =
        copyToList(
            getSubjectGenerator()
                .getSampleElements(getSubjectGenerator().getCollectionSize().getNumElements()));
    sort(entries, Helpers.<K, V>entryComparator(navigableMap.comparator()));

    // some tests assume SEVERAL == 3
    if (entries.size() >= 1) {

  @Override
  public void setUp() throws Exception {
    super.setUp();
    navigableMap = (NavigableMap<K, V>) getMap();
    entries =
        copyToList(
            getSubjectGenerator()
                .getSampleElements(getSubjectGenerator().getCollectionSize().getNumElements()));
    sort(entries, Helpers.<K, V>entryComparator(navigableMap.comparator()));

    // some tests assume SEVERAL == 3
    if (entries.size() >= 1) {

  @CollectionSize.Require(absent = {ZERO, ONE})
  public void testIndexOf_duplicate() {
    E[] array = createSamplesArray();
    array[getNumElements() / 2] = e0();
    collection = getSubjectGenerator().create(array);
    assertEquals(
        "indexOf(duplicate) should return index of first occurrence", 0, getList().indexOf(e0()));
  }

  @CollectionSize.Require(absent = {ZERO, ONE})
  public void testLastIndexOf_duplicate() {
    E[] array = createSamplesArray();
    array[getNumElements() / 2] = e0();
    collection = getSubjectGenerator().create(array);
    assertEquals(
        "lastIndexOf(duplicate) should return index of last occurrence",
        getNumElements() / 2,
        getList().lastIndexOf(e0()));
  }

public class MultisetContainsTester<E> extends AbstractMultisetTester<E> {
  @CollectionSize.Require(absent = ZERO)
  public void testContainsAllMultisetIgnoresFrequency() {
    assertTrue(getMultiset().containsAll(getSubjectGenerator().create(e0(), e0(), e0())));
  }

  @CollectionSize.Require(absent = ZERO)
  public void testContainsAllListIgnoresFrequency() {
    assertTrue(getMultiset().containsAll(asList(e0(), e0(), e0())));
  }

public class MultisetContainsTester<E> extends AbstractMultisetTester<E> {
  @CollectionSize.Require(absent = ZERO)
  public void testContainsAllMultisetIgnoresFrequency() {
    assertTrue(getMultiset().containsAll(getSubjectGenerator().create(e0(), e0(), e0())));
  }

  @CollectionSize.Require(absent = ZERO)
  public void testContainsAllListIgnoresFrequency() {
    assertTrue(getMultiset().containsAll(asList(e0(), e0(), e0())));
  }

public class AbstractMultisetTester<E> extends AbstractCollectionTester<E> {
  protected final Multiset<E> getMultiset() {
    return (Multiset<E>) collection;
  }

  protected void initThreeCopies() {
    collection = getSubjectGenerator().create(e0(), e0(), e0());
  }