This is not a limitation of **FastAPI**, it's part of the HTTP protocol.

///

## Optional File Upload { #optional-file-upload }

You can make a file optional by using standard type annotations and setting a default value of `None`:

{* ../../docs_src/request_files/tutorial001_02_an_py310.py hl[9,17] *}

import org.codelibs.fess.opensearch.user.exentity.Group;
import org.codelibs.fess.util.ComponentUtil;
import org.codelibs.fess.util.RenderDataUtil;
import org.dbflute.optional.OptionalEntity;
import org.dbflute.optional.OptionalThing;
import org.lastaflute.web.Execute;
import org.lastaflute.web.response.HtmlResponse;
import org.lastaflute.web.response.render.RenderData;

import org.codelibs.fess.opensearch.config.exentity.RelatedQuery;
import org.codelibs.fess.util.ComponentUtil;
import org.codelibs.fess.util.RenderDataUtil;
import org.dbflute.optional.OptionalEntity;
import org.dbflute.optional.OptionalThing;
import org.lastaflute.web.Execute;
import org.lastaflute.web.response.HtmlResponse;
import org.lastaflute.web.response.render.RenderData;

import org.codelibs.fess.opensearch.config.exbhv.KeyMatchBhv;
import org.codelibs.fess.opensearch.config.exentity.KeyMatch;
import org.dbflute.cbean.result.PagingResultBean;
import org.dbflute.optional.OptionalEntity;

import jakarta.annotation.Resource;

/**
 * Service class for KeyMatch.
 */
public class KeyMatchService extends FessAppService {

    /** The KeyMatch behavior. */
    @Resource

    /**
     * The network name of the share.
     */
    protected String netName;
    /**
     * The type of the share (e.g., disk, printer, IPC).
     */
    protected int type;
    /**
     * The optional comment or description for the share.
     */
    protected String remark;

    /**
     * Default constructor for SmbShareInfo.
     */
    public SmbShareInfo() {
    }

    /**

import org.codelibs.fess.opensearch.config.exentity.BoostDocumentRule;
import org.codelibs.fess.util.ComponentUtil;
import org.codelibs.fess.util.RenderDataUtil;
import org.dbflute.optional.OptionalEntity;
import org.dbflute.optional.OptionalThing;
import org.lastaflute.web.Execute;
import org.lastaflute.web.response.HtmlResponse;
import org.lastaflute.web.response.render.RenderData;

## First dependency "dependable" { #first-dependency-dependable }

You could create a first dependency ("dependable") like:

{* ../../docs_src/dependencies/tutorial005_an_py310.py hl[8:9] *}

It declares an optional query parameter `q` as a `str`, and then it just returns it.

This is quite simple (not very useful), but will help us focus on how the sub-dependencies work.

import org.codelibs.fess.opensearch.config.exbhv.BoostDocumentRuleBhv;
import org.codelibs.fess.opensearch.config.exentity.BoostDocumentRule;
import org.dbflute.cbean.result.PagingResultBean;
import org.dbflute.optional.OptionalEntity;

import jakarta.annotation.Resource;

/**
 * Service class for boost document rule management operations.
 * Provides CRUD operations for boost document rules.
 */

import org.codelibs.fess.opensearch.config.exentity.WebConfig;
import org.codelibs.fess.util.ComponentUtil;
import org.codelibs.fess.util.RenderDataUtil;
import org.dbflute.optional.OptionalEntity;
import org.dbflute.optional.OptionalThing;
import org.lastaflute.web.Execute;
import org.lastaflute.web.response.HtmlResponse;
import org.lastaflute.web.response.render.RenderData;

# OkHttp test platform rules uses optional classes.