It's **not supported** by Pydantic to have a model of Pydantic v2 with its own fields defined as Pydantic v1 models or vice versa.

```mermaid
graph TB
    subgraph "❌ Not Supported"
        direction TB
        subgraph V2["Pydantic v2 Model"]
            V1Field["Pydantic v1 Model"]
        end
        subgraph V1["Pydantic v1 Model"]
            V2Field["Pydantic v2 Model"]
        end
    end

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.mylasta.direction.sponsor;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.function.BiConsumer;

import org.codelibs.fess.annotation.Secured;
import org.codelibs.fess.app.web.base.FessAdminAction;
import org.codelibs.fess.mylasta.direction.FessConfig;
import org.codelibs.fess.util.ComponentUtil;
import org.codelibs.fess.util.RenderDataUtil;
import org.lastaflute.core.direction.ObjectiveConfig;
import org.lastaflute.web.Execute;
import org.lastaflute.web.response.HtmlResponse;
import org.lastaflute.web.response.render.RenderData;

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
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;

   */
  Set<N> adjacentNodes(N node);

  /**
   * Returns a live view of all nodes in this graph adjacent to {@code node} which can be reached by
   * traversing {@code node}'s incoming edges <i>against</i> the direction (if any) of the edge.
   *
   * <p>In an undirected graph, this is equivalent to {@link #adjacentNodes(Object)}.
   *
   * <p>If {@code node} is removed from the graph after this method is called, the {@code Set}

### 같은 앱에서 Pydantic v1과 v2 함께 사용하기 { #pydantic-v1-and-v2-on-the-same-app }

Pydantic에서는 Pydantic v2 모델의 필드를 Pydantic v1 모델로 정의하거나 그 반대로 하는 것을 **지원하지 않습니다**.

```mermaid
graph TB
    subgraph "❌ Not Supported"
        direction TB
        subgraph V2["Pydantic v2 Model"]
            V1Field["Pydantic v1 Model"]
        end
        subgraph V1["Pydantic v1 Model"]
            V2Field["Pydantic v2 Model"]
        end
    end

 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.job;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.codelibs.fess.mylasta.direction.FessConfig;
import org.codelibs.fess.opensearch.client.SearchEngineClient;
import org.codelibs.fess.util.ComponentUtil;
import org.opensearch.index.query.QueryBuilder;
import org.opensearch.index.query.QueryBuilders;

        fractionalBuilder.add(d * scale).add(-d * scale);
      }
    }
    for (int i = Double.MIN_EXPONENT; i <= Double.MAX_EXPONENT; i++) {
      for (int direction : new int[] {1, -1}) {
        double d = Double.longBitsToDouble(Double.doubleToLongBits(Math.scalb(1.0, i)) + direction);
        // Math.nextUp/nextDown
        if (d != Math.rint(d)) {
          fractionalBuilder.add(d);
        }
      }
    }

```

This will regenerate:
- `src/main/java/org/codelibs/fess/mylasta/action/FessLabels.java`
- `src/main/java/org/codelibs/fess/mylasta/action/FessMessages.java`
- `src/main/java/org/codelibs/fess/mylasta/direction/FessProp.java`

### 5. Rebuild the Project

```bash
mvn clean package
```

### 6. Test the New Language

1. **Start Fess:**
   ```bash
   # Run the main class in your IDE

import org.codelibs.fess.crawler.client.http.config.WebAuthenticationConfig;
import org.codelibs.fess.helper.SystemHelper;
import org.codelibs.fess.mylasta.direction.FessConfig;
import org.codelibs.fess.mylasta.direction.FessProp;
import org.codelibs.fess.unit.UnitFessTestCase;
import org.codelibs.fess.util.ComponentUtil;
import org.junit.jupiter.api.Test;
import org.opensearch.common.SetOnce;