}

            @Override
            public <T> Optional<T> lookupOptional(Class<T> type) {
                return Optional.empty();
            }

            @Override
            public <T> Optional<T> lookupOptional(Class<T> type, String name) {
                return Optional.empty();
            }

            @Override

 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.mylasta.direction.sponsor;

import java.util.TimeZone;

import org.dbflute.optional.OptionalObject;
import org.dbflute.optional.OptionalThing;
import org.dbflute.util.DfTypeUtil;
import org.lastaflute.web.ruts.process.ActionRuntime;
import org.lastaflute.web.servlet.request.RequestManager;

import org.codelibs.fess.opensearch.config.exentity.DuplicateHost;
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;

#### `Optional`

Вы также можете использовать `Optional`, чтобы объявить, что переменная имеет тип, например, `str`, но это является «необязательным», что означает, что она также может быть `None`:

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

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;

/**
 * Service for managing stopwords.
 * This class provides methods to interact with stopwords dictionaries,

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;

/**
 * Service for managing synonyms.
 * This class provides methods to interact with synonym dictionaries,

 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.api.services;

import java.util.Optional;

import org.apache.maven.api.ExtensibleEnum;
import org.apache.maven.api.Service;
import org.apache.maven.api.annotations.Nonnull;

/**

 */
package org.codelibs.fess.mylasta.direction.sponsor;

import java.util.Locale;

import org.dbflute.jdbc.ClassificationMeta;
import org.dbflute.optional.OptionalObject;
import org.dbflute.optional.OptionalThing;
import org.lastaflute.db.dbflute.classification.ListedClassificationProvider;
import org.lastaflute.db.dbflute.exception.ProvidedClassificationNotFoundException;

/**

   * implementations.
   */
  SUPPORTS_SET;

  /**
   * A set containing none of the optional features of the {@link Iterator} or {@link ListIterator}
   * interfaces.
   */
  public static final Set<IteratorFeature> UNMODIFIABLE = emptySet();

  /**
   * A set containing all of the optional features of the {@link Iterator} and {@link ListIterator}
   * interfaces.
   */

set maven.conf default ${maven.home}/conf
set maven.installation.conf default ${maven.conf}

[plexus.core]
load       ${maven.conf}/logging
optionally ${maven.home}/lib/ext/redisson/*.jar
optionally ${maven.home}/lib/ext/hazelcast/*.jar
optionally ${user.home}/.m2/ext/*.jar
optionally ${maven.home}/lib/ext/*.jar
load       ${maven.home}/lib/maven-*.jar