assertEquals("multiset.count(null) didn't return 0", 0, getMultiset().count(null));
  }

  @CollectionFeature.Require(absent = ALLOWS_NULL_QUERIES)
  public void testCount_null_forbidden() {
    assertThrows(NullPointerException.class, () -> getMultiset().count(null));
  }

  @CollectionSize.Require(absent = ZERO)
  @CollectionFeature.Require(ALLOWS_NULL_VALUES)
  public void testCount_nullPresent() {

  }

  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = ZERO)
  public void testRemove_unsupported() {
    assertThrows(UnsupportedOperationException.class, () -> collection.remove(e0()));
    expectUnchanged();
    assertTrue("remove(present) should not remove the element", collection.contains(e0()));
  }

  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)

  @ListFeature.Require(SUPPORTS_ADD_WITH_INDEX)
  @CollectionSize.Require(absent = ZERO)
  public void testAddAtIndex_supportedPresent() {
    getList().add(0, e0());
    expectAdded(0, e0());
  }

  @ListFeature.Require(absent = SUPPORTS_ADD_WITH_INDEX)
  @CollectionSize.Require(absent = ZERO)
  /*
   * absent = ZERO isn't required, since unmodList.add() must

  @CollectionSize.Require(absent = ZERO)
  public void testSubList_subListRemoveAffectsOriginal() {
    List<E> subList = getList().subList(0, 1);
    subList.remove(0);
    List<E> expected = asList(createSamplesArray()).subList(1, getNumElements());
    expectContents(expected);
  }

  @ListFeature.Require(SUPPORTS_REMOVE_WITH_INDEX)
  @CollectionSize.Require(absent = ZERO)

  @CollectionSize.Require(absent = ZERO)
  public void testSubList_subListRemoveAffectsOriginal() {
    List<E> subList = getList().subList(0, 1);
    subList.remove(0);
    List<E> expected = asList(createSamplesArray()).subList(1, getNumElements());
    expectContents(expected);
  }

  @ListFeature.Require(SUPPORTS_REMOVE_WITH_INDEX)
  @CollectionSize.Require(absent = ZERO)

              });
    } catch (UnsupportedOperationException tolerated) {
    }
    expectUnchanged();
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testComputeIfPresent_unsupportedPresent() {
    assertThrows(
        UnsupportedOperationException.class, () -> getMap().computeIfPresent(k0(), (k, v) -> v3()));
    expectUnchanged();
  }

  @ListFeature.Require(SUPPORTS_SET)
  @CollectionSize.Require(absent = ZERO)
  public void testSet() {
    doTestSet(e3());
  }

  @CollectionSize.Require(absent = ZERO)
  @CollectionFeature.Require(ALLOWS_NULL_VALUES)
  @ListFeature.Require(SUPPORTS_SET)
  public void testSet_null() {
    doTestSet(null);
  }

  @CollectionSize.Require(absent = ZERO)
  @CollectionFeature.Require(ALLOWS_NULL_VALUES)

@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class SetCreationTester<E> extends AbstractSetTester<E> {
  @CollectionFeature.Require(value = ALLOWS_NULL_VALUES, absent = REJECTS_DUPLICATES_AT_CREATION)
  @CollectionSize.Require(absent = {ZERO, ONE})
  public void testCreateWithDuplicates_nullDuplicatesNotRejected() {
    E[] array = createArrayWithNullElement();
    array[0] = null;

@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class SetCreationTester<E> extends AbstractSetTester<E> {
  @CollectionFeature.Require(value = ALLOWS_NULL_VALUES, absent = REJECTS_DUPLICATES_AT_CREATION)
  @CollectionSize.Require(absent = {ZERO, ONE})
  public void testCreateWithDuplicates_nullDuplicatesNotRejected() {
    E[] array = createArrayWithNullElement();
    array[0] = null;

public class MapComputeTester<K, V> extends AbstractMapTester<K, V> {
  @MapFeature.Require({SUPPORTS_PUT, SUPPORTS_REMOVE})
  public void testCompute_absentToPresent() {
    assertEquals(
        "Map.compute(absent, functionReturningValue) should return value",
        v3(),
        getMap()
            .compute(
                k3(),
                (k, v) -> {
                  assertEquals(k3(), k);