}
    assertEquals(
        "A Set's hashCode() should be the sum of those of its elements.",
        expectedHashCode,
        getSet().hashCode());
  }

  @CollectionSize.Require(absent = CollectionSize.ZERO)
  @CollectionFeature.Require(ALLOWS_NULL_VALUES)
  public void testHashCode_containingNull() {
    Collection<E> elements = getSampleElements(getNumElements() - 1);
    int expectedHashCode = 0;

@SuppressWarnings("JUnit4ClassUsedInJUnit3")
@IgnoreJRERequirement // We opt into library desugaring for our tests.
public class CollectionForEachTester<E> extends AbstractCollectionTester<E> {
  @CollectionFeature.Require(absent = KNOWN_ORDER)
  public void testForEachUnknownOrder() {
    List<E> elements = new ArrayList<>();
    collection.forEach(elements::add);
    Helpers.assertEqualIgnoringOrder(asList(createSamplesArray()), elements);
  }

  public void testToArray_noArg() {
    Object[] actual = getList().toArray();
    assertArrayEquals("toArray() order should match list", createOrderedArray(), actual);
  }

  @CollectionSize.Require(absent = ZERO)
  public void testToArray_tooSmall() {
    Object[] actual = getList().toArray(new Object[0]);
    assertArrayEquals("toArray(tooSmall) order should match list", createOrderedArray(), actual);
  }

  public void testOffer_nullSupported() {
    assertTrue("offer(null) should return true", getQueue().offer(null));
    expectAdded((E) null);
  }

  @CollectionFeature.Require(value = SUPPORTS_ADD, absent = ALLOWS_NULL_VALUES)
  public void testOffer_nullUnsupported() {
    assertThrows(NullPointerException.class, () -> getQueue().offer(null));
    expectUnchanged();

        com.google.common.base.Optional.absent(),
        generator.generateFresh(new TypeToken<com.google.common.base.Optional<String>>() {}));
    assertEquals(
        com.google.common.base.Optional.of("2"),
        generator.generateFresh(new TypeToken<com.google.common.base.Optional<String>>() {}));
    // Test that the first generated instance for different cgcb.Optional<T> is always absent().

  val tag: Long,
  /** Encode and decode the value once tags are handled. */
  private val codec: Codec<T>,
  /** True if the default value should be used if this value is absent during decoding. */
  val isOptional: Boolean = false,
  /** The value to return if this value is absent. Undefined unless this is optional. */
  val defaultValue: T? = null,
  /** True to set the encoded or decoded value as the type hint for the current SEQUENCE. */

  public void testPollFirst() {
    assertEquals(a, navigableSet.pollFirst());
    assertEquals(values.subList(1, values.size()), copyToList(navigableSet));
  }

  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
  public void testPollFirstUnsupported() {
    assertThrows(UnsupportedOperationException.class, () -> navigableSet.pollFirst());
  }

  @CollectionSize.Require(SEVERAL)

   * Returns the size of this source in bytes, if the size can be easily determined without actually
   * opening the data stream.
   *
   * <p>The default implementation returns {@link Optional#absent}. Some sources, such as a file,
   * 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 bytes than would be returned by reading all of the bytes (for

        assertGet(key, expectedValues);
        assertEquals(value, values.get(values.size() - 1));
      }
    }
  }

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testPutDuplicateValue() {
    List<Entry<K, V>> entries = copyToList(multimap().entries());

    for (Entry<K, V> entry : entries) {
      resetContainer();

      K k = entry.getKey();

    return implied;
  }

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

    MapFeature[] absent() default {};
  }