// ===================================================================================
    //                                                                           Attribute
    //                                                                           =========
    @Resource
    private CrawlingInfoService crawlingInfoService;
    @Resource
    private CrawlingInfoPager crawlingInfoPager;

    // ===================================================================================
    //                                                                           Attribute
    //                                                                           =========
    @Resource
    private DataConfigService dataConfigService;

    // ===================================================================================
    //                                                                           Attribute
    //                                                                           =========
    @Resource
    protected DynamicProperties systemProperties;

    // ===================================================================================
    //                                                                           Attribute
    //                                                                           =========
    @Resource
    private RelatedQueryService relatedQueryService;
    @Resource
    private RelatedQueryPager relatedQueryPager;

    // ===================================================================================
    //                                                                           Attribute
    //
    @Resource
    protected DynamicProperties systemProperties;

    @Resource
    protected WebConfigService webConfigService;

    @Resource
    protected FileConfigService fileConfigService;

* For `PUT` requests to `/items/{item_id}`, read the body as JSON:
    * Check that it has a required attribute `name` that should be a `str`.
    * Check that it has a required attribute `price` that has to be a `float`.
    * Check that it has an optional attribute `is_offer`, that should be a `bool`, if present.
    * All this would also work for deeply nested JSON objects.

    // Constant
    //
    private static final Logger logger = LogManager.getLogger(ApiAdminSearchlistAction.class);

    // ===================================================================================
    // Attribute
    // =========
    @Resource
    protected SearchHelper searchHelper;

    @Resource
    protected SearchEngineClient searchEngineClient;

public class ApiAdminStatsAction extends FessApiAdminAction {

    // ===================================================================================
    //                                                                           Attribute
    //                                                                           =========

    // ===================================================================================

        private boolean sourceLevelSet = false;

        public void setSourceLevel(String sourceLevel) {
            if (sourceLevelSet) {
                throw new IllegalStateException("Cannot reset sourceLevel attribute; it is already set to: " + sourceLevel);
            } else if (!(USER_LEVEL.equals(sourceLevel) || GLOBAL_LEVEL.equals(sourceLevel))) {

Use standard Python types for all the attributes:

{* ../../docs_src/body/tutorial001_py310.py hl[5:9] *}


The same as when declaring query parameters, when a model attribute has a default value, it is not required. Otherwise, it is required. Use `None` to make it just optional.

For example, this model above declares a JSON "`object`" (or Python `dict`) like:

```JSON
{
    "name": "Foo",