/**
   * Quasi-implementation of {@link ListIterator} that works from a list of elements and a set of
   * features to support (from the enclosing {@link AbstractIteratorTester} instance). Instead of
   * throwing exceptions like {@link NoSuchElementException} at the appropriate times, it throws
   * {@link PermittedMetaException} instances, which wrap a set of all exceptions that the iterator

    long bitSize() {
      return (long) data.length() * Long.SIZE;
    }

    /**
     * Number of set bits (1s).
     *
     * <p>Note that because of concurrent set calls and uses of atomics, this bitCount is a (very)
     * close *estimate* of the actual number of bits set. It's not possible to do better than an
     * estimate without locking. Note that the number, if not exactly accurate, is *always*

      return null;
    }
    return set(rowIndex, columnIndex, null);
  }

  // TODO(jlevy): Add eraseRow and eraseColumn methods?

  @Override
  public int size() {
    return rowList.size() * columnList.size();
  }

  /**
   * Returns an unmodifiable set of all row key / column key / value triplets. Changes to the table
   * will update the returned set.
   *

     * @see jcifs.DfsReferralData#getDomain()
     */
    @Override
    public String getDomain() {
        return this.domain;
    }

    /**
     * Set the domain for this referral
     *
     * @param domain
     *            the domain to set
     */
    public void setDomain(final String domain) {
        this.domain = domain;
    }

    @Override
    public String getLink() {

{* ../../docs_src/body_nested_models/tutorial002.py hl[14] *}

## 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:

{* ../../docs_src/body_nested_models/tutorial003.py hl[1,14] *}

덕분에 중복 데이터가 있는 요청을 수신하더라도 고유한 항목들의 집합으로 변환됩니다.

그리고 해당 데이터를 출력 할 때마다 소스에 중복이 있더라도 고유한 항목들의 집합으로 출력됩니다.

  private static final class HashSetSupplier<V extends @Nullable Object>
      implements Supplier<Set<V>>, Serializable {
    private final int expectedValuesPerKey;

    HashSetSupplier(int expectedValuesPerKey) {
      this.expectedValuesPerKey = checkNonnegative(expectedValuesPerKey, "expectedValuesPerKey");
    }

    @Override
    public Set<V> get() {
      return Platform.newHashSetWithExpectedSize(expectedValuesPerKey);
    }

  private static final class HashSetSupplier<V extends @Nullable Object>
      implements Supplier<Set<V>>, Serializable {
    private final int expectedValuesPerKey;

    HashSetSupplier(int expectedValuesPerKey) {
      this.expectedValuesPerKey = checkNonnegative(expectedValuesPerKey, "expectedValuesPerKey");
    }

    @Override
    public Set<V> get() {
      return Platform.newHashSetWithExpectedSize(expectedValuesPerKey);
    }

* `frozenset`:
    * 📨 & 📨, 😥 🎏 `set`:
        * 📨, 📇 🔜 ✍, ❎ ❎ & 🏭 ⚫️ `set`.
        * 📨, `set` 🔜 🗜 `list`.
        * 🏗 🔗 🔜 ✔ 👈 `set` 💲 😍 (⚙️ 🎻 🔗 `uniqueItems`).
* `bytes`:
    * 🐩 🐍 `bytes`.
    * 📨 & 📨 🔜 😥 `str`.
    * 🏗 🔗 🔜 ✔ 👈 ⚫️ `str` ⏮️ `binary` "📁".
* `Decimal`:

import com.google.common.annotations.GwtCompatible;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import org.jspecify.annotations.Nullable;

/**
 * A {@link ListenableFuture} whose result can be set by a {@link #set(Object)}, {@link
 * #setException(Throwable)} or {@link #setFuture(ListenableFuture)} call. It can also, like any
 * other {@code Future}, be {@linkplain #cancel cancelled}.
 *

  public SampleElements<AnEnum> samples() {
    return new Enums();
  }

  @Override
  public Set<AnEnum> create(Object... elements) {
    AnEnum[] array = new AnEnum[elements.length];
    int i = 0;
    for (Object e : elements) {
      array[i++] = (AnEnum) e;
    }
    return create(array);
  }

  protected abstract Set<AnEnum> create(AnEnum[] elements);

  @Override
  public AnEnum[] createArray(int length) {