<version>1.2.0</version>
          <models>
            <model>src/main/mdo/metadata.mdo</model>
          </models>
          <templates>
            <template>model.vm</template>
          </templates>
          <params>
            <param>packageModelV4=org.apache.maven.api.metadata</param>
          </params>
        </configuration>
        <executions>

  <build>
    <plugins>
      <plugin>
        <groupId>org.codehaus.modello</groupId>
        <artifactId>modello-maven-plugin</artifactId>
        <configuration>
          <version>1.2.0</version>
          <models>
            <model>src/main/mdo/core-extensions.mdo</model>
          </models>
          <templates>
            <template>model.vm</template>
          </templates>
          <params>

      <plugin>
        <groupId>org.codehaus.modello</groupId>
        <artifactId>modello-maven-plugin</artifactId>
        <configuration>
          <version>2.0.0</version>
          <velocityBasedir>${project.basedir}/../../src/mdo</velocityBasedir>
          <models>
            <model>src/main/mdo/settings.mdo</model>
          </models>
          <templates>
            <template>model.vm</template>
          </templates>

      </plugin>
      <plugin>
        <groupId>org.codehaus.modello</groupId>
        <artifactId>modello-maven-plugin</artifactId>
        <configuration>
          <version>1.0.0</version>
          <models>
            <model>src/main/mdo/profiles.mdo</model>
            <model>src/main/mdo/paramdoc.mdo</model>
          </models>
        </configuration>
        <executions>
          <execution>

  specific language governing permissions and limitations
  under the License.
-->

<model xmlns="http://codehaus-plexus.github.io/MODELLO/2.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://codehaus-plexus.github.io/MODELLO/2.0.0 https://codehaus-plexus.github.io/modello/xsd/modello-2.0.0.xsd"
  xml.namespace="http://maven.apache.org/SETTINGS/${version}"

 * under the License.
 */
package org.apache.maven.model.normalization;

import org.apache.maven.model.Model;
import org.apache.maven.model.building.ModelBuildingRequest;
import org.apache.maven.model.building.ModelProblemCollector;

/**
 * Handles normalization of a model. In this context, normalization is the process of producing a canonical
 * representation for models that physically look different but are semantically equivalent.
 *

            </goals>
            <configuration>
              <version>4.0.0</version>
              <models>
                <model>target/mdo/maven.mdo</model>
              </models>
              <templates>
                <template>src/main/mdo/model-v3.vm</template>
                <template>src/main/mdo/merger.vm</template>
                <template>src/main/mdo/transformer.vm</template>

  |   definition of these types
  |
-->
<model xmlns="http://codehaus-plexus.github.io/MODELLO/2.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://codehaus-plexus.github.io/MODELLO/2.0.0 https://codehaus-plexus.github.io/modello/xsd/modello-2.0.0.xsd"
  xml.namespace="http://maven.apache.org/POM/${version}"

import org.apache.maven.model.DistributionManagement;
import org.apache.maven.model.Exclusion;
import org.apache.maven.model.Extension;
import org.apache.maven.model.FileSet;
import org.apache.maven.model.InputLocation;
import org.apache.maven.model.IssueManagement;
import org.apache.maven.model.License;
import org.apache.maven.model.MailingList;
import org.apache.maven.model.Model;
import org.apache.maven.model.ModelBase;

Und es wird entsprechend annotiert/dokumentiert.

## Verschachtelte Modelle { #nested-models }

Jedes Attribut eines Pydantic-Modells hat einen Typ.

Aber dieser Typ kann selbst ein anderes Pydantic-Modell sein.

Sie können also tief verschachtelte JSON-„Objekte“ deklarieren, mit spezifischen Attributnamen, -typen, und -validierungen.