//

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

    // ===================================================================================
    //                                                                               Hook

Now use the parameter `callbacks` in *your API's path operation decorator* to pass the attribute `.routes` (that's actually just a `list` of routes/*path operations*) from that callback router:

{* ../../docs_src/openapi_callbacks/tutorial001.py hl[35] *}

/// tip

Notice that you are not passing the router itself (`invoices_callback_router`) to `callback=`, but the attribute `.routes`, as in `invoices_callback_router.routes`.

///

You can reuse FastAPI's internal functions to create the HTML pages for the docs, and pass them the needed arguments:

* `openapi_url`: the URL where the HTML page for the docs can get the OpenAPI schema for your API. You can use here the attribute `app.openapi_url`.
* `title`: the title of your API.
* `oauth2_redirect_url`: you can use `app.swagger_ui_oauth2_redirect_url` here to use the default.

        assertEquals(0x8000, SmbConstants.CAP_LARGE_WRITEX);
        assertEquals(0x80000000, SmbConstants.CAP_EXTENDED_SECURITY);
    }

    @Test
    @DisplayName("Should define file attribute constants")
    void testFileAttributes() {
        assertEquals(0x01, SmbConstants.ATTR_READONLY);
        assertEquals(0x02, SmbConstants.ATTR_HIDDEN);
        assertEquals(0x04, SmbConstants.ATTR_SYSTEM);

        super();
    }

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

    /** The user service for managing user settings. */
    @Resource
    private UserService userService;

    /**

    protected PathMappingHelper pathMappingHelper;

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

    // ===================================================================================
    //                                                                               Hook

        super();
    }

    // ===================================================================================
    //                                                                           Attribute
    //                                                                           =========
    /** System properties for dynamic configuration management */
    @Resource
    protected DynamicProperties systemProperties;

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

    // ===================================================================================
    //                                                                               Hook

    /**
     * Processes WEB-INF/lib directory and additionally scans WEB-INF/plugin for Fess plugins.
     * This method extends the standard processing to include plugin JAR files that contain
     * the "Fess-WebAppJar" manifest attribute.
     *
     * @throws LifecycleException if an error occurs during processing
     */
    @Override
    protected void processWebInfLib() throws LifecycleException {
        super.processWebInfLib();

Remember that when you import `Query`, `Path`, and others from `fastapi`, those are actually functions that return special classes.

///

/// tip

Notice how each model's attribute with a type, default value and `Field` has the same structure as a *path operation function's* parameter, with `Field` instead of `Path`, `Query` and `Body`.

///

## Add extra information { #add-extra-information }