And these models are all sharing a lot of the data and duplicating attribute names and types.

We could do better.

We can declare a `UserBase` model that serves as a base for our other models. And then we can make subclasses of that model that inherit its attributes (type declarations, validation, etc).

    /** The time taken to execute the search query in milliseconds. */
    protected final long queryTime;

    /** Flag indicating whether the search results are partial due to timeout or other constraints. */
    protected final boolean partialResults;

    /** The facet response containing aggregated facet information for the search results. */
    protected final FacetResponse facetResponse;

    /**

 * then Lock B, while another thread acquires Lock B, and then Lock A:
 *
 * <pre>
 * Thread1: acquire(LockA) --X acquire(LockB)
 * Thread2: acquire(LockB) --X acquire(LockA)
 * </pre>
 *
 * <p>Neither thread will progress because each is waiting for the other. In more complex
 * applications, cycles can arise from interactions among more than 2 locks:
 *

import org.eclipse.aether.RepositorySystem;
import org.eclipse.aether.RepositorySystemSession;
import org.eclipse.aether.RequestTrace;
import org.eclipse.aether.artifact.Artifact;
import org.eclipse.aether.artifact.DefaultArtifact;
import org.eclipse.aether.impl.RemoteRepositoryManager;
import org.eclipse.aether.repository.RemoteRepository;
import org.eclipse.aether.resolution.ArtifactRequest;

   */
  ALLOWS_NULL_QUERIES,
  ALLOWS_NULL_VALUES(ALLOWS_NULL_QUERIES),

  /**
   * Indicates that a collection disallows certain elements (other than {@code null}, whose validity
   * as an element is indicated by the presence or absence of {@link #ALLOWS_NULL_VALUES}). From the
   * documentation for {@link Collection}:
   *
   * <blockquote>
   *

    Optional<Boolean> infer();

    /**
     * Should fix Maven 4 compatibility issues in POMs.
     * This includes fixing unsupported combine attributes, duplicate dependencies,
     * unsupported expressions, and other Maven 4 validation issues.
     *
     * @return an {@link Optional} containing the boolean value {@code true} if specified, or empty
     */
    @Nonnull
    Optional<Boolean> model();

    /**

 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * 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 com.google.common.collect;

    protected long currentEndRecordNumber;

    /** List of page numbers for pagination navigation. */
    protected List<String> pageNumberList;

    /** Flag indicating whether the results are partial due to timeout or other issues. */
    protected boolean partialResults;

    /** The actual search query executed against the search engine. */
    protected String searchQuery;

    /** Time taken to execute the search query in milliseconds. */

work stoppage, computer failure or malfunction, or any and all other 
commercial damages or losses), even if such Contributor has been advised of 
the possibility of such damages. 

9. Accepting Warranty or Additional Liability. While redistributing the Work 
or Derivative Works thereof, You may choose to offer, and charge a fee for, 
acceptance of support, warranty, indemnity, or other liability obligations 

import org.eclipse.aether.RepositoryEvent;
import org.eclipse.aether.RepositoryEvent.EventType;
import org.eclipse.aether.RepositoryListener;
import org.eclipse.aether.RepositorySystem;
import org.eclipse.aether.RepositorySystemSession;
import org.eclipse.aether.RequestTrace;
import org.eclipse.aether.SessionData;
import org.eclipse.aether.metadata.DefaultMetadata;