And your *path operation* has a little lock in the top-right corner that you can click.

///

And if you click it, you have a little authorization form to type a `username` and `password` (and other optional fields):

<img src="/img/tutorial/security/image02.png">

/// note

It doesn't matter what you type in the form, it won't work yet. But we'll get there.

///

<img src="/img/tutorial/response-model/image02.png">

## 응답 모델 인코딩 매개변수

응답 모델은 아래와 같이 기본값을 가질 수 있습니다:

{* ../../docs_src/response_model/tutorial004.py hl[11,13:14] *}

* `description: Optional[str] = None`은 기본값으로 `None`을 갖습니다.
* `tax: float = 10.5`는 기본값으로 `10.5`를 갖습니다.
* `tags: List[str] = []` 빈 리스트의 기본값으로: `[]`.

그러나 실제로 저장되지 않았을 경우 결과에서 값을 생략하고 싶을 수 있습니다.

	"gopkg.in/yaml.v3"
)

// expire: # Expire objects that match a condition
//   apiVersion: v1
//   bucket: mybucket # Bucket where this batch job will expire matching objects from
//   prefix: myprefix # (Optional) Prefix under which this job will expire objects matching the rules below.
//   rules:
//     - type: object  # regular objects with zero or more older versions

```Python hl_lines="9  14"
from typing import Optional

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
async def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
async def read_item(item_id: int, q: Optional[str] = None):
    return {"item_id": item_id, "q": q}
```

**توجه**:

import org.codelibs.fess.util.ComponentUtil;
import org.dbflute.bhv.readable.EntityRowHandler;
import org.dbflute.cbean.result.ListResultBean;
import org.dbflute.cbean.result.PagingResultBean;
import org.dbflute.optional.OptionalEntity;

import com.orangesignal.csv.CsvConfig;
import com.orangesignal.csv.CsvReader;
import com.orangesignal.csv.CsvWriter;

import jakarta.annotation.Resource;

/**

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.base.Function;
import com.google.common.base.Optional;
import com.google.common.base.Predicate;
import com.google.common.collect.FluentIterable;
import com.google.common.collect.ImmutableListMultimap;
import com.google.common.collect.ImmutableMultimap;

import org.dbflute.cbean.ConditionBean;
import org.dbflute.cbean.result.ListResultBean;
import org.dbflute.cbean.result.PagingResultBean;
import org.dbflute.exception.IllegalBehaviorStateException;
import org.dbflute.optional.OptionalEntity;
import org.dbflute.util.DfTypeUtil;
import org.opensearch.action.bulk.BulkRequestBuilder;
import org.opensearch.action.delete.DeleteRequestBuilder;
import org.opensearch.action.index.IndexRequestBuilder;

import jakarta.servlet.http.HttpServletRequest;

import org.codelibs.fess.mylasta.direction.FessConfig;
import org.codelibs.fess.unit.UnitFessTestCase;
import org.codelibs.fess.util.ComponentUtil;
import org.dbflute.optional.OptionalThing;
import org.lastaflute.web.path.ActionPathResolver;
import org.lastaflute.web.ruts.process.ActionRuntime;
import org.lastaflute.web.servlet.request.RequestManager;

 */
package org.codelibs.fess.util;

import java.io.File;
import java.io.FilenameFilter;
import java.nio.file.Path;

import org.codelibs.fess.unit.UnitFessTestCase;
import org.dbflute.optional.OptionalEntity;

public class ResourceUtilTest extends UnitFessTestCase {
    public void test_resolve() {
        String value;

        value = null;
        assertNull(ResourceUtil.resolve(value));

You can define arbitrarily deeply nested models:

{* ../../docs_src/body_nested_models/tutorial007_py310.py hl[7,12,18,21,25] *}

/// info

Notice how `Offer` has a list of `Item`s, which in turn have an optional list of `Image`s

///

## Bodies of pure lists { #bodies-of-pure-lists }