* @see org.apache.maven.api.services.ArtifactManager#getPath(Artifact)
     */
    @Nonnull
    default Optional<ProducedArtifact> getMainArtifact() {
        List<ProducedArtifact> artifacts = getArtifacts();
        return artifacts.size() == 2 ? Optional.of(artifacts.get(1)) : Optional.empty();
    }

    /**

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!}
```

---

## FastAPI installieren

Der erste Schritt besteht aus der Installation von FastAPI.

Für dieses Tutorial empfiehlt es sich, FastAPI mit allen optionalen Abhängigkeiten und Funktionen zu installieren:

<div class="termy">

```console
$ pip install "fastapi[all]"

---> 100%
```

</div>

  /** Puts all the associations from {@code rangeMap} into this range map (optional operation). */
  void putAll(RangeMap<K, ? extends V> rangeMap);

  /** Removes all associations from this range map (optional operation). */
  void clear();

  /**
   * Removes all associations from this range map in the specified range (optional operation).
   *

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,

     *
     * @see Function
     * @see Optional
     * @see HashMap#computeIfAbsent(Object, Function)
     */
    static UnaryOperator<String> memoize(UnaryOperator<String> callback) {
        Map<String, Optional<String>> cache = new HashMap<>();
        return s -> cache.computeIfAbsent(s, v -> Optional.ofNullable(callback.apply(v)))
                .orElse(null);
    }

                    }
                }

                @Nonnull
                @Override
                public Optional<org.apache.maven.api.Toolchain> createDefaultToolchain()
                        throws ToolchainFactoryException {
                    return Optional.ofNullable(v3Factory.createDefaultToolchain())
                            .map(ToolchainManagerFactory.this::getToolchainV4);
                }

 * 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;