* 変数`prices`は`dict`であり:
    * この`dict`のキーは`str`型です。（つまり、各項目の名前）
    * この`dict`の値は`float`型です。（つまり、各項目の価格）

#### `Optional`

また、`Optional`を使用して、変数が`str`のような型を持つことを宣言することもできますが、それは「オプション」であり、`None`にすることもできます。

```Python hl_lines="1 4"
{!../../docs_src/python_types/tutorial009.py!}
```

ただの`str`の代わりに`Optional[str]`を使用することで、エディタは値が常に`str`であると仮定している場合に実際には`None`である可能性があるエラーを検出するのに役立ちます。

#### ジェネリック型

import org.codelibs.fess.app.web.base.FessSearchAction;
import org.codelibs.fess.app.web.login.LoginAction;
import org.codelibs.fess.mylasta.action.FessUserBean;
import org.codelibs.fess.util.ComponentUtil;
import org.dbflute.optional.OptionalThing;
import org.lastaflute.web.Execute;
import org.lastaflute.web.response.HtmlResponse;

public class LogoutAction extends FessSearchAction {

import org.codelibs.fess.es.config.exentity.FileAuthentication;
import org.codelibs.fess.mylasta.direction.FessConfig;
import org.codelibs.fess.util.ParameterUtil;
import org.dbflute.cbean.result.PagingResultBean;
import org.dbflute.optional.OptionalEntity;

import jakarta.annotation.Resource;

public class FileAuthenticationService {

    @Resource
    protected FileAuthenticationBhv fileAuthenticationBhv;

    @Resource

import org.codelibs.fess.es.config.exbhv.RoleTypeBhv;
import org.codelibs.fess.es.config.exentity.RoleType;
import org.codelibs.fess.mylasta.direction.FessConfig;
import org.dbflute.cbean.result.PagingResultBean;
import org.dbflute.optional.OptionalEntity;

import jakarta.annotation.Resource;

public class RoleTypeService {

    @Resource
    protected RoleTypeBhv roleTypeBhv;

    @Resource
    protected FessConfig fessConfig;

import org.codelibs.fess.dict.DictionaryManager;
import org.codelibs.fess.dict.stopwords.StopwordsFile;
import org.codelibs.fess.dict.stopwords.StopwordsItem;
import org.codelibs.fess.mylasta.direction.FessConfig;
import org.dbflute.optional.OptionalEntity;

import jakarta.annotation.Resource;

public class StopwordsService {
    @Resource
    protected DictionaryManager dictionaryManager;

    @Resource
    protected FessConfig fessConfig;

import org.codelibs.fess.dict.DictionaryManager;
import org.codelibs.fess.dict.synonym.SynonymFile;
import org.codelibs.fess.dict.synonym.SynonymItem;
import org.codelibs.fess.mylasta.direction.FessConfig;
import org.dbflute.optional.OptionalEntity;

import jakarta.annotation.Resource;

public class SynonymService {
    @Resource
    protected DictionaryManager dictionaryManager;

    @Resource
    protected FessConfig fessConfig;

type Error struct {
	Code    int    // The HTTP status code returned to the client
	APICode string // The API error code identifying the error
	Err     string // The error message returned to the client
	Cause   error  // Optional, lower level error cause.
}

func (e Error) Error() string {
	if e.Cause == nil {
		return e.Err
	}
	return fmt.Sprintf("%s: %v", e.Err, e.Cause)
}

func errKeyCreationFailed(err error) Error {

import org.codelibs.fess.es.config.exentity.PathMapping;
import org.codelibs.fess.mylasta.direction.FessConfig;
import org.codelibs.fess.util.ComponentUtil;
import org.dbflute.cbean.result.PagingResultBean;
import org.dbflute.optional.OptionalEntity;

import jakarta.annotation.Resource;

public class PathMappingService extends FessAppService {

    @Resource
    protected PathMappingBhv pathMappingBhv;

    @Resource

import org.codelibs.fess.es.config.exentity.DuplicateHost;
import org.codelibs.fess.mylasta.direction.FessConfig;
import org.dbflute.cbean.result.PagingResultBean;
import org.dbflute.optional.OptionalEntity;

import jakarta.annotation.Resource;

public class DuplicateHostService extends FessAppService {

    @Resource
    protected DuplicateHostBhv duplicateHostBhv;

    @Resource

import org.codelibs.fess.dict.DictionaryManager;
import org.codelibs.fess.dict.kuromoji.KuromojiFile;
import org.codelibs.fess.dict.kuromoji.KuromojiItem;
import org.codelibs.fess.mylasta.direction.FessConfig;
import org.dbflute.optional.OptionalEntity;

import jakarta.annotation.Resource;

public class KuromojiService {
    @Resource
    protected DictionaryManager dictionaryManager;

    @Resource
    protected FessConfig fessConfig;