}

  @CollectionFeature.Require(absent = ALLOWS_NULL_QUERIES)
  public void testContains_nullNotContainedAndUnsupported() {
    expectNullMissingWhenNullUnsupported("contains(null) should return false or throw");
  }

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

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(ZERO)
  public void testPutWithSameValueFails() {
    getMap().put(k0(), v0());
    assertThrows(IllegalArgumentException.class, () -> getMap().put(k1(), v0()));
    // verify that the bimap is unchanged
    expectAdded(e0());
  }

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(ZERO)

public class MapCreationTester<K, V> extends AbstractMapTester<K, V> {
  @MapFeature.Require(ALLOWS_NULL_KEYS)
  @CollectionSize.Require(absent = ZERO)
  public void testCreateWithNullKeySupported() {
    initMapWithNullKey();
    expectContents(createArrayWithNullKey());
  }

  @MapFeature.Require(absent = ALLOWS_NULL_KEYS)
  @CollectionSize.Require(absent = ZERO)
  public void testCreateWithNullKeyUnsupported() {

    } catch (UnsupportedOperationException tolerated) {
    }
  }

  @CollectionSize.Require(absent = ZERO)
  @CollectionFeature.Require(SUPPORTS_ADD)
  public void testSetCount_oneToOne_addSupported() {
    assertOneToOne();
  }

  @CollectionSize.Require(absent = ZERO)
  @CollectionFeature.Require(SUPPORTS_REMOVE)
  public void testSetCount_oneToOne_removeSupported() {
    assertOneToOne();
  }

public class MultisetEntrySetTester<E> extends AbstractMultisetTester<E> {

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  public void testEntrySet_clear() {
    getMultiset().entrySet().clear();
    assertTrue("multiset not empty after entrySet().clear()", getMultiset().isEmpty());
  }

  @CollectionSize.Require(ONE)
  @CollectionFeature.Require(SUPPORTS_ITERATOR_REMOVE)
  public void testEntrySet_iteratorRemovePropagates() {

      }
    }
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require({ALLOWS_NULL_KEYS, ALLOWS_NULL_VALUES})
  public void testContainsEntryNullYes() {
    initMultimapWithNullKeyAndValue();
    assertTrue(multimap().containsEntry(null, null));
  }

  @MapFeature.Require({ALLOWS_NULL_KEY_QUERIES, ALLOWS_NULL_VALUE_QUERIES})
  public void testContainsEntryNullNo() {

  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = ZERO)
  public void testClearPropagatesToGet() {
    for (K key : sampleKeys()) {
      resetContainer();
      Collection<V> collection = multimap().get(key);
      multimap().clear();
      assertEmpty(collection);
    }
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = ZERO)

  @ListFeature.Require(SUPPORTS_REMOVE_WITH_INDEX)
  @CollectionSize.Require(absent = {ZERO, ONE})
  public void testRemoveAtIndex_middle() {
    runRemoveTest(getNumElements() / 2);
  }

  @CollectionFeature.Require(FAILS_FAST_ON_CONCURRENT_MODIFICATION)
  @ListFeature.Require(SUPPORTS_REMOVE_WITH_INDEX)
  @CollectionSize.Require(absent = ZERO)
  public void testRemoveAtIndexConcurrentWithIteration() {
    assertThrows(

  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ZERO)
  public void testEmptyMultisetPollLast() {
    assertNull(sortedMultiset.pollLastEntry());
  }

  @CollectionSize.Require(ONE)
  public void testSingletonMultisetFirst() {
    assertEquals(a, sortedMultiset.firstEntry());
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ONE)

@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class ListRetainAllTester<E> extends AbstractListTester<E> {
  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = {ZERO, ONE})
  public void testRetainAll_duplicatesKept() {
    E[] array = createSamplesArray();
    array[1] = e0();
    collection = getSubjectGenerator().create(array);
    assertFalse(