*/
@GwtCompatible(serializable = true)
@ElementTypesAreNonnullByDefault
final class JdkBackedImmutableSet<E> extends IndexedImmutableSet<E> {
  private final Set<?> delegate;
  private final ImmutableList<E> delegateList;

  JdkBackedImmutableSet(Set<?> delegate, ImmutableList<E> delegateList) {
    this.delegate = delegate;
    this.delegateList = delegateList;
  }

  @Override
  E get(int index) {

@REM
@REM Environment Variable Prerequisites
@REM
@REM   JAVA_HOME           (Optional) Points to a Java installation.
@REM   MAVEN_BATCH_ECHO    (Optional) Set to 'on' to enable the echoing of the batch commands.
@REM   MAVEN_BATCH_PAUSE   (Optional) set to 'on' to wait for a key stroke before ending.
@REM   MAVEN_OPTS          (Optional) Java runtime options used when Maven is executed.

  @Override
  @Test
  public void nodes_checkReturnedSetMutability() {
    Set<Integer> nodes = network.nodes();
    assertThrows(UnsupportedOperationException.class, () -> nodes.add(N2));
    addNode(N1);
    assertThat(network.nodes()).containsExactlyElementsIn(nodes);
  }

  @Override
  @Test
  public void edges_checkReturnedSetMutability() {
    Set<String> edges = network.edges();

          .suppressing(parentBuilder.getSuppressedTests())
          .createTestSuite();
    }
  }

  @Override
  Set<Feature<?>> computeMultimapGetFeatures(Set<Feature<?>> multimapFeatures) {
    Set<Feature<?>> derivedFeatures = super.computeMultimapGetFeatures(multimapFeatures);
    if (derivedFeatures.contains(CollectionFeature.SUPPORTS_ADD)) {

     * plugin and build extensions realms to avoid presence of duplicate and possibly conflicting classes on classpath.
     */
    private final Set<String> providedArtifacts;

    private final Set<String> providedArtifactsV4;

    @Inject
    public DefaultClassRealmManager(
            CoreRealm coreRealm, List<ClassRealmManagerDelegate> delegates, CoreExports exports) {

```Python hl_lines="14"
{!../../docs_src/body_nested_models/tutorial002.py!}
```

## 집합 타입

그런데 생각해보니 태그는 반복되면 안 되고, 고유한(Unique) 문자열이어야 할 것 같습니다.

그리고 파이썬은 집합을 위한 특별한 데이터 타입 `set`이 있습니다.

그렇다면 `Set`을 임포트 하고 `tags`를 `str`의 `set`으로 선언할 수 있습니다:

```Python hl_lines="1  14"
{!../../docs_src/body_nested_models/tutorial003.py!}
```

덕분에 중복 데이터가 있는 요청을 수신하더라도 고유한 항목들의 집합으로 변환됩니다.

  @Override
  public Set<Cell<R, C, V>> cellSet() {
    return delegate().cellSet();
  }

  @Override
  public void clear() {
    delegate().clear();
  }

  @Override
  public Map<R, V> column(@ParametricNullness C columnKey) {
    return delegate().column(columnKey);
  }

  @Override
  public Set<C> columnKeySet() {
    return delegate().columnKeySet();
  }

import com.google.common.collect.ImmutableSet;
import java.util.HashSet;
import java.util.Set;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

@RunWith(JUnit4.class)
public final class InvalidatableSetTest {
  Set<Integer> wrappedSet;
  Set<Integer> copyOfWrappedSet;
  InvalidatableSet<Integer> setToTest;

  @Before
  public void createSets() {

    assertThat(map).containsEntry(one, two);

    // TODO(cgruber): Confirm with fry@ that this is a reasonable substitute.
    // Set<Entry<Object, Object>> entries = map.entrySet();
    // assertThat(entries).containsExactly(
    //    Maps.immutableEntry(three, one), Maps.immutableEntry(one, two));
    // Set<Object> keys = map.keySet();
    // assertThat(keys).containsExactly(one, three);
    // Collection<Object> values = map.values();

    }
  }

  static <E extends @Nullable Object> Collection<E> filterCollection(
      Collection<E> collection, Predicate<? super E> predicate) {
    if (collection instanceof Set) {
      return Sets.filter((Set<E>) collection, predicate);
    } else {
      return Collections2.filter(collection, predicate);
    }
  }

  @Override
  public boolean containsKey(@CheckForNull Object key) {