Then we can declare `tags` as a set of strings:

{* ../../docs_src/body_nested_models/tutorial003_py310.py hl[12] *}

With this, even if you receive a request with duplicate data, it will be converted to a set of unique items.

And whenever you output that data, even if the source had duplicates, it will be output as a set of unique items.

And it will be annotated / documented accordingly too.

## Nested Models { #nested-models }

      default:
        return new RegularImmutableSet<E>(delegate);
    }
  }

  private static <E> ImmutableSet<E> create(E... elements) {
    // Create the set first, to remove duplicates if necessary.
    Set<E> set = Sets.newLinkedHashSet();
    Collections.addAll(set, elements);
    for (E element : set) {
      checkNotNull(element);
    }

    switch (set.size()) {
      case 0:

   * returns a {@link SortedSet}, instead of the {@link Collection} specified in the {@link
   * Multimap} interface.
   *
   * <p>Any duplicates in {@code values} will be stored in the multimap once.
   */
  @CanIgnoreReturnValue
  @Override
  public SortedSet<V> replaceValues(@ParametricNullness K key, Iterable<? extends V> values) {

 *   <li>Deleting URL queues associated with a session.</li>
 *   <li>Deleting all URL queues.</li>
 *   <li>Offering a list of URLs to the queue, ensuring duplicates are not added.</li>
 *   <li>Polling (retrieving and removing) a URL from the queue.</li>
 *   <li>Saving the session (currently a no-op).</li>
 *   <li>Checking if a URL has already been visited.</li>

        return getSubjectGenerator().create(e0(), e1(), e1(), e2()).iterator();
      }
    }.test();
  }

  /**
   * Returns {@link Method} instances for the tests that assume multisets support duplicates so that
   * the test of {@code Multisets.forSet()} can suppress them.
   */
  @J2ktIncompatible
  @GwtIncompatible // reflection
  public static List<Method> getIteratorDuplicateInitializingMethods() {

  /**
   * Returns a {@code Collector} that accumulates the input elements into a new {@code
   * ImmutableSortedSet}, ordered by the specified comparator.
   *
   * <p>If the elements contain duplicates (according to the comparator), only the first duplicate
   * in encounter order will appear in the result.
   *
   * @since 33.2.0 (available since 21.0 in guava-jre)
   */

        Map<String, String> queryMap = facetQueryView.getQueryMap();

        // Should not duplicate existing pdf query
        assertEquals("filetype:pdf", queryMap.get("existing_pdf"));
        // Should add doc since it's not present
        assertEquals("filetype:doc", queryMap.get("DOC"));

        // Check no duplicate queries added to FacetInfo
        List<String> addedQueries = testFacetInfo.getAddedQueries();

     *   <li>Scope updates (if the scope was changed during resolution)</li>
     *   <li>Conflict resolution information (if the dependency was omitted due to conflicts or duplicates)</li>
     * </ul>
     *
     * @return a string representation of this dependency node with optional detailed information
     */
    @Nonnull
    String asString();

    /**

        }
        if (elements.length > 0) {
          multiset1.add(elements[0]);
        }
        if (elements.length > 1) {
          /*
           * When a test requests a multiset with duplicates, our plan of
           * "add an extra item 0 to A and an extra item 1 to B" really means
           * "add an extra item 0 to A and B," which isn't what we want.
           */

   * returns a {@link SortedSet}, instead of the {@link java.util.Collection} specified in the
   * {@link Multimap} interface.
   *
   * <p>Any duplicates in {@code values} will be stored in the multimap once.
   */
  @CanIgnoreReturnValue
  @Override
  SortedSet<V> replaceValues(@ParametricNullness K key, Iterable<? extends V> values);

  /**