List<String> temp = new ArrayList<>();
    for (Feature<?> feature : features) {
      Object featureAsObject = feature; // to work around bogus JDK warning
      if (featureAsObject instanceof Enum) {
        Enum<?> f = (Enum<?>) featureAsObject;
        temp.add(f.getDeclaringClass().getSimpleName() + "." + feature);
      } else {
        temp.add(feature.toString());
      }
    }
    return temp.toString();
  }

Jika ada *operasi path* yang menerima *parameter path*, tetapi anda ingin nilai valid *parameter path* sudah terdefinisi, anda bisa menggunakan standar Python <abbr title="Enumeration">`Enum`</abbr>.

### Membuat class `Enum`

Import `Enum` dan buat *sub-class* warisan dari `str` dan `Enum`.

Dengan warisan dari `str` dokumen API mengetahui nilai nya harus berjenis `string` supaya bisa digunakan dengan benar.

import java.util.Iterator;

@GwtCompatible
@J2ktIncompatible
public final class EnumMultiset<E extends Enum<E>> extends AbstractMapBasedMultiset<E>
    implements Serializable {
  public static <E extends Enum<E>> EnumMultiset<E> create(Class<E> type) {
    return new EnumMultiset<>(new EnumMap<E, Count>(type));
  }

  public static <E extends Enum<E>> EnumMultiset<E> create(Iterable<E> elements) {
    Iterator<E> iterator = elements.iterator();

  }

  static BigInteger listProduct(List<BigInteger> nums) {
    return listProduct(nums, 0, nums.size());
  }

  static BigInteger listProduct(List<BigInteger> nums, int start, int end) {
    switch (end - start) {
      case 0:
        return BigInteger.ONE;
      case 1:
        return nums.get(start);
      case 2:
        return nums.get(start).multiply(nums.get(start + 1));
      case 3:

### Bir `Enum` Sınıfı Oluşturalım

`Enum` sınıfını projemize dahil edip `str` ile `Enum` sınıflarını miras alan bir alt sınıf yaratalım.

 */
@GwtCompatible
@J2ktIncompatible
public final class EnumHashBiMap<K extends Enum<K>, V extends @Nullable Object>
    extends AbstractBiMap<K, V> {
  transient Class<K> keyTypeOrObjectUnderJ2cl;

  /**
   * Returns a new, empty {@code EnumHashBiMap} using the specified key type.
   *
   * @param keyType the key type
   */
  public static <K extends Enum<K>, V extends @Nullable Object> EnumHashBiMap<K, V> create(
      Class<K> keyType) {

  }

  @IgnoreJRERequirement // see enclosing class (whose annotation Animal Sniffer ignores here...)
  private static final class EnumSetAccumulator<E extends Enum<E>> {
    @SuppressWarnings({"rawtypes", "unchecked"})
    static final Collector<Enum<?>, ?, ImmutableSet<? extends Enum<?>>> TO_IMMUTABLE_ENUM_SET =
        (Collector) toImmutableEnumSetGeneric();

    private @Nullable EnumSet<E> set;

    void add(E e) {

        EnumSetAccumulator::toImmutableSet,
        Collector.Characteristics.UNORDERED);
  }

  private static final class EnumSetAccumulator<E extends Enum<E>> {
    @SuppressWarnings({"rawtypes", "unchecked"})
    static final Collector<Enum<?>, ?, ImmutableSet<? extends Enum<?>>> TO_IMMUTABLE_ENUM_SET =
        (Collector) toImmutableEnumSetGeneric();

    private @Nullable EnumSet<E> set;

    void add(E e) {

import java.util.Set;

import org.dbflute.utflute.core.PlainTestCase;

/**
 * Test class for CrawlerStatus enum.
 * Tests all enum functionality including values, valueOf, ordinal, and serialization.
 */
public class CrawlerStatusTest extends PlainTestCase {

    /**
     * Test that all expected enum values exist
     */
    public void test_enumValues() {
        CrawlerStatus[] values = CrawlerStatus.values();

 *
 * @author Mike Bostock
 * @since 2.0
 */
@GwtCompatible
@J2ktIncompatible
public final class EnumBiMap<K extends Enum<K>, V extends Enum<V>> extends AbstractBiMap<K, V> {
  /*
   * J2CL's EnumMap does not need the Class instance, so we can use Object.class instead. (Or we