And Python has a special data type for sets of unique items, the `set`.

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.

```JSON hl_lines="22"
{
    "openapi": "3.0.2",
    "info": {
        "title": "FastAPI",
        "version": "0.1.0"
    },
    "paths": {
        "/items/": {
            "get": {
                "summary": "Read Items",
                "operationId": "read_items_items__get",
                "responses": {
                    "200": {
                        "description": "Successful Response",

### Die resultierende Response

Wenn der Client `http://example.com/items/foo` anfragt (ein `item_id` `"foo"`), erhält dieser Client einen HTTP-Statuscode 200 und folgende JSON-Response:

```JSON
{
  "item": "The Foo Wrestlers"
}
```

    * `url` (**обов'язково**): `str`з URL-адресою зовнішньої документації.

### Створення метаданих для тегів

Спробуймо це на прикладі з тегами для `users` та `items`.

Створіть метадані для своїх тегів і передайте їх у параметр  `openapi_tags`:

{* ../../docs_src/metadata/tutorial004.py hl[3:16,18] *}

                                            <tbody>
                                            <c:forEach var="data" varStatus="s"
                                                       items="${accessTokenItems}">
                                                <tr
                                                        data-href="${contextPath}/admin/accesstoken/details/4/${f:u(data.id)}">

For example, if the client tries to send a `tool` query parameter with a value of `plumbus`, like:

```http
https://example.com/items/?limit=10&tool=plumbus
```

They will receive an **error** response telling them that the query parameter `tool` is not allowed:

```json
{
    "detail": [
        {
            "type": "extra_forbidden",

```

</div>

## ✅ ⚫️

👆 🔜 💪 ✅ ⚫️ 👆 ☁ 📦 📛, 🖼: <a href="http://192.168.99.100/items/5?q=somequery" class="external-link" target="_blank">http://192.168.99.100/items/5?q=somequery</a> ⚖️ <a href="http://127.0.0.1/items/5?q=somequery" class="external-link" target="_blank">http://127.0.0.1/items/5?q=somequery</a> (⚖️ 🌓, ⚙️ 👆 ☁ 🦠).

👆 🔜 👀 🕳 💖:

```JSON
{"item_id": 5, "q": "somequery"}
```

    }

    /**
     * Retrieves a specific stemmer override item by dictionary ID and item ID.
     *
     * @param dictId The ID of the stemmer override dictionary
     * @param id The unique ID of the stemmer override item to retrieve
     * @return An OptionalEntity containing the stemmer override item if found, empty otherwise
     */

                                                <la:option value=""/>
                                                <c:forEach var="hn" varStatus="s"
                                                           items="${handlerNameItems}">
                                                    <la:option value="${f:u(hn.value)}">${f:h(hn.label)}</la:option>
                                                </c:forEach>

                                            <c:forEach var="p" varStatus="s"
                                                       items="${pager.pageNumberList}">
                                                <li
                                                        <c:if test="${p == pager.currentPageNumber}">class="page-item active"</c:if>>
                                                    <la:link