*/
  public void testAdd_unsupportedPresent() {
    assertThrows(UnsupportedOperationException.class, () -> getList().add(e0()));
  }

  @CollectionFeature.Require(value = {SUPPORTS_ADD, ALLOWS_NULL_VALUES})
  @CollectionSize.Require(absent = ZERO)
  public void testAdd_supportedNullPresent() {
    E[] array = createArrayWithNullElement();
    collection = getSubjectGenerator().create(array);

		return nil, etcdErrToErr(err, client.Endpoints())
	}
	if resp.Count == 0 {
		return nil, errConfigNotFound
	}
	for _, ev := range resp.Kvs {
		if string(ev.Key) == key {
			return ev.Value, nil
		}
	}
	return nil, errConfigNotFound

	for tier, stat := range t.requestsCount {
		metrics = append(metrics, MetricV2{
			Description:    tierRequestsSuccessMD,
			Value:          float64(stat.success),
			VariableLabels: map[string]string{"tier": tier},
		})
		metrics = append(metrics, MetricV2{
			Description:    tierRequestsFailureMD,
			Value:          float64(stat.failure),
			VariableLabels: map[string]string{"tier": tier},
		})
	}
	return metrics
}

	}
	if a.Format != "" {
		f := strings.ToLower(a.Format)
		if f != event.NamespaceFormat && f != event.AccessFormat {
			return errors.New("format value unrecognized")
		}
	}
	if a.Index == "" {
		return errors.New("empty index value")
	}

	if (a.Username == "" && a.Password != "") || (a.Username != "" && a.Password == "") {
		return errors.New("username and password should be set in pairs")
	}

   * returns the expected data.
   *
   * @throws Throwable if the listener isn't called or if it resulted in a throwable or if the
   *     result doesn't match the expected value.
   */
  public void assertSuccess(Object expectedData) throws Throwable {
    // Verify that the listener executed in a reasonable amount of time.
    Assert.assertTrue(countDownLatch.await(1L, SECONDS));

    try {

    assertEquals(
        "size1Collection.toString should return [{element}]",
        "[" + e0() + "]",
        collection.toString());
  }

  @CollectionSize.Require(SEVERAL)
  @CollectionFeature.Require(value = KNOWN_ORDER, absent = NON_STANDARD_TOSTRING)
  public void testToString_sizeSeveral() {
    String expected = copyToList(getOrderedElements()).toString();

  public void testContains_wrongType() {
    try {
      // noinspection SuspiciousMethodCalls
      assertFalse(
          "containsValue(wrongType) should return false or throw",
          getMap().containsValue(WrongType.VALUE));
    } catch (ClassCastException tolerated) {
    }
  }

// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@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();

    assertEquals(
        "size1Collection.toString should return [{element}]",
        "[" + e0() + "]",
        collection.toString());
  }

  @CollectionSize.Require(SEVERAL)
  @CollectionFeature.Require(value = KNOWN_ORDER, absent = NON_STANDARD_TOSTRING)
  public void testToString_sizeSeveral() {
    String expected = copyToList(getOrderedElements()).toString();

// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@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();