Set<Feature<?>> moreAbsentFeatures = moreRequirements.getAbsentFeatures();
    checkConflict("absent", absentFeatures, "present", morePresentFeatures, source);
    checkConflict("present", presentFeatures, "absent", moreAbsentFeatures, source);
    presentFeatures.addAll(morePresentFeatures);
    absentFeatures.addAll(moreAbsentFeatures);
    return requirements;
  }

  boolean allowsSelfLoops = false;
  ElementOrder<N> nodeOrder = ElementOrder.insertion();
  ElementOrder<N> incidentEdgeOrder = ElementOrder.unordered();

  Optional<Integer> expectedNodeCount = Optional.absent();

  /**
   * Creates a new instance with the specified edge directionality.
   *
   * @param directed if true, creates an instance for graphs whose edges are each directed; if

        expectedHashCode,
        getMap().hashCode());
  }

  @CollectionSize.Require(absent = CollectionSize.ZERO)
  @MapFeature.Require(ALLOWS_NULL_KEYS)
  public void testHashCode_containingNullKey() {
    Entry<K, V> entryWithNull = entry(null, v3());
    runEntryWithNullTest(entryWithNull);
  }

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

  public void testKeySet() {
    for (Entry<K, V> entry : getSampleElements()) {
      assertTrue(multimap().keySet().contains(entry.getKey()));
    }
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(ALLOWS_NULL_KEYS)
  public void testKeySetContainsNullKeyPresent() {
    initMultimapWithNullKey();
    assertTrue(multimap().keySet().contains(null));
  }

   * opening the data stream.
   *
   * <p>The default implementation returns {@link Optional#absent}. Some sources, such as a {@code
   * CharSequence}, may return a non-absent value. Note that in such cases, it is <i>possible</i>
   * that this method will return a different number of chars than would be returned by reading all
   * of the chars.
   *

   * opening the data stream.
   *
   * <p>The default implementation returns {@link Optional#absent}. Some sources, such as a {@code
   * CharSequence}, may return a non-absent value. Note that in such cases, it is <i>possible</i>
   * that this method will return a different number of chars than would be returned by reading all
   * of the chars.
   *

@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class CollectionSpliteratorTester<E> extends AbstractCollectionTester<E> {

  @CollectionFeature.Require(absent = KNOWN_ORDER)
  public void testSpliteratorUnknownOrder() {
    SpliteratorTester.of(collection::spliterator).expect(getSampleElements());
  }

  @CollectionFeature.Require(KNOWN_ORDER)

@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class MultisetAddTester<E> extends AbstractMultisetTester<E> {
  @CollectionFeature.Require(absent = SUPPORTS_ADD)
  public void testAddUnsupported() {
    assertThrows(UnsupportedOperationException.class, () -> getMultiset().add(e0()));
  }

  @CollectionFeature.Require(SUPPORTS_ADD)

    return implied;
  }

  @Retention(RetentionPolicy.RUNTIME)
  @Inherited
  @TesterAnnotation
  public @interface Require {
    SetFeature[] value() default {};

    SetFeature[] absent() default {};
  }

    return emptySet();
  }

  @Retention(RetentionPolicy.RUNTIME)
  @Inherited
  @TesterAnnotation
  public @interface Require {
    MultisetFeature[] value() default {};

    MultisetFeature[] absent() default {};
  }