new EqualsTester()
        .addEqualityGroup(Equivalence.equals().pairwise(), Equivalence.equals().pairwise())
        .addEqualityGroup(Equivalence.identity().pairwise())
        .testEquals();
  }

  private enum LengthFunction implements Function<String, Integer> {
    INSTANCE;

    @Override
    public Integer apply(String input) {
      return input.length();
    }
  }

              + " but returned result: "
              + result);
    } else {
      throw new AssertionError("expected to throw " + expectedThrowable.getSimpleName());
    }
  }

  private enum PlatformSpecificExceptionBatch {
    PLATFORM {
      @GwtIncompatible
      @J2ktIncompatible
      @Override
      // returns the types available in "normal" environments

本例中有 3 个查询参数：

* `needy`，必选的 `str` 类型参数
* `skip`，默认值为 `0` 的 `int` 类型参数
* `limit`，可选的 `int` 类型参数

/// tip | 提示

还可以像在[路径参数](path-params.md#_8){.internal-link target=_blank} 中那样使用 `Enum`。

   *   <li>normalNullable: only second param is Nullable
   *   <li>nullableNullable: both params are Nullable
   * </ul>
   */
  public static class TwoArg {
    /** Action to take on a null param. */
    public enum Action {
      THROW_A_NPE {
        @Override
        public void act() {
          throw new NullPointerException();
        }
      },
      THROW_OTHER {
        @Override

// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class MapEntrySetTester<K, V> extends AbstractMapTester<K, V> {
  private enum IncomparableType {
    INSTANCE;
  }

  @CollectionSize.Require(ONE)
  @CollectionFeature.Require(SUPPORTS_ITERATOR_REMOVE)
  public void testIteratorRemoveOnly() {
    Set<Entry<K, V>> entrySet = getMap().entrySet();

// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class MapEntrySetTester<K, V> extends AbstractMapTester<K, V> {
  private enum IncomparableType {
    INSTANCE;
  }

  @CollectionSize.Require(ONE)
  @CollectionFeature.Require(SUPPORTS_ITERATOR_REMOVE)
  public void testIteratorRemoveOnly() {
    Set<Entry<K, V>> entrySet = getMap().entrySet();

    this.equivalence = checkNotNull(equivalence);
  }

  /**
   * Different orderings for combining the elements of an input array, which must all produce the
   * same result.
   */
  enum CollectStrategy {
    /** Get one accumulator and accumulate the elements into it sequentially. */
    SEQUENTIAL {
      @Override
      final <T extends @Nullable Object, A extends @Nullable Object, R extends @Nullable Object>

  // methods of this class.
  private long count = 0;
  private double mean = 0.0; // any finite value will do, we only use it to multiply by zero for sum
  private double sumOfSquaresOfDeltas = 0.0;
  private double min = NaN; // any value will do
  private double max = NaN; // any value will do

  /** Adds the given value to the dataset. */
  public void add(double value) {

* o servidor
* o cliente

* o provedor de nuvem
* o serviço de nuvem

* o desenvolvimento
* as etapas de desenvolvimento

* o dict
* o dicionário
* a enumeração
* o enum
* o membro do enum

* o codificador
* o decodificador
* codificar
* decodificar

* a exceção
* lançar

* a expressão
* a instrução

* o frontend
* o backend

     *             or if after unwrapping, the parameter values cannot be converted to the corresponding formal parameter types,
     *             or if the constructor is related to an enum type
     * @see Constructor#newInstance(Object[])
     */
    public static <T> T newInstance(final Class<T> clazz) throws InstantiationRuntimeException, IllegalAccessRuntimeException {