List<ToolchainModel> models = session.getRequest().getToolchains().get(type);

        return selectToolchains(models, type, requirements);
    }

    private List<Toolchain> selectToolchains(
            List<ToolchainModel> models, String type, Map<String, String> requirements) {
        List<Toolchain> toolchains = new ArrayList<>();

        if (models != null) {

Does nothing. false true false false false true generate-sources org.apache.maven.plugin.coreit.CMojo java per-lookup once-per-session models java.lang.String[] false true version java.lang.String false true ${version} xpp3-writer Does nothing. false true false false false true generate-sources org.apache.maven.plugin.coreit.BMojo java per-lookup once-per-session models java.lang.String[] false true version java.lang.String false true ${version} org.apache.maven maven-plugin-api jar 2.0 org/apache/m...

    boolean isResolveDependencies();

    /**
     * Controls the level of validation to perform on processed models. By default, models are validated in strict mode.
     *
     * @param validationLevel The level of validation to perform on processed models, e.g.
     *            {@link org.apache.maven.model.building.ModelBuildingRequest#VALIDATION_LEVEL_STRICT}.
     * @return This configuration, never {@code null}.
     */

     */
    private static final Map<String, Model> SUPER_MODELS = new ConcurrentHashMap<>();

    @Inject
    public DefaultSuperPomProvider(ModelProcessor modelProcessor) {
        this.modelProcessor = modelProcessor;
    }

    @Override
    public Model getSuperPom(String version) {
        return SUPER_MODELS.computeIfAbsent(Objects.requireNonNull(version), v -> readModel(version, v));
    }

 * The maven super model

 * how parent poms are processed

 * the order in which elements in the POM are overridden

 * minimum element-set for a valid project pom


Maven super model

 Inheritance is recursive in Maven but there is a special model which is the implicit super parent in the lineage
 of models you may specify:

              <velocityBasedir>${project.basedir}/../../src/mdo</velocityBasedir>
              <version>2.0.0</version>
              <models>
                <model>src/main/mdo/plugin.mdo</model>
              </models>
              <templates>
                <template>model.vm</template>
              </templates>
              <params>
                <param>packageModelV4=org.apache.maven.api.plugin.descriptor</param>

     *
     * @param modelId The identifier of the desired raw model, must not be {@code null}.
     * @return The raw model or {@code null} if the specified model id does not refer to a known model.
     */
    @Nonnull
    Optional<Model> getRawModel(@Nonnull String modelId);

    /**
     * Gets the profiles from the specified model that were active during model building. The model identifier should be

      </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>

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

import java.util.function.Supplier;

import org.apache.maven.api.services.Source;

/**
 * Caches auxiliary data used during model building like already processed raw/effective models. The data in the cache
 * is meant for exclusive consumption by the model builder and is opaque to the cache implementation. The cache key is

/**
 * A test which demonstrates maven's recursive inheritance where
 * a distinct value is taken from each parent contributing to
 * the final model of the project being assembled. There is no
 * overriding going on amongst the models being used in this test:
 * each model in the lineage is providing a value that is not present
 * anywhere else in the lineage. We are just making sure that values