throws ModelBuilderException {
        problems.setSource(childModel);

        Parent parent = childModel.getParent();

        String groupId = parent.getGroupId();
        String artifactId = parent.getArtifactId();
        String version = parent.getVersion();

        ModelResolver modelResolver = getModelResolver(request);
        Objects.requireNonNull(

<project>
  <parent>
    <artifactId>maven</artifactId>
    <groupId>org.apache.maven</groupId>
    <version>2.0</version>
  </parent>
  <modelVersion>4.0.0</modelVersion>
  <groupId>org.apache.maven</groupId>
  <artifactId>maven-plugin-api</artifactId>
  <name>Maven Plugin API</name>
  <version>2.0</version>
  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.13.1</version>

<?xml version="1.0" encoding="UTF-8"?>
<metadata>
  <groupId>org.apache.maven.its</groupId>
  <artifactId>parent</artifactId>
  <version>0.1</version>
  <versioning>
    <versions>
      <version>0.1</version>
    </versions>
  </versioning>

 * TODO: add request trace so that requests can be linked together and through the resolver
 * TODO: add a Request interface holding session + parent request
 *
 * @since 4.0.0
 */
@Experimental
@ThreadSafe
public interface Session {

    @Nonnull
    Settings getSettings();

    @Nonnull
    LocalRepository getLocalRepository();

        final Parent parent = Parent.newBuilder()
                .groupId("org.apache")
                .artifactId("apache")
                .version("1")
                .build();

        assertNotNull(this.newModelResolver().resolveModel(session, parent, new AtomicReference<>()));
        assertEquals("1", parent.getVersion());
    }

    @Test

         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <!-- Shared parent. Doesn't define a lot of things about Apache like general mailing lists, but does
       define the settings common to all projects at Apache -->
  <groupId>org.apache</groupId>
  <artifactId>apache</artifactId>

    <modelVersion>4.0.0</modelVersion>

    <groupId>org.apache.maven.its</groupId>
    <artifactId>parent</artifactId>
    <version>0.1</version>
    <packaging>pom</packaging>

    <name>Maven Integration Test :: Dummy Parent</name>

    <build>
        <pluginManagement>
            <plugins>
                <plugin>

import org.apache.maven.api.model.Parent;

/**
 * Resolves a POM from its coordinates.
 */
public interface ModelResolver extends Service {

    /**
     * Tries to resolve the POM for the specified parent coordinates possibly updating {@code parent}.
     *
     * @param session The session to use to resolve the model, must not be {@code null}.
     * @param parent The parent coordinates to resolve, must not be {@code null}.

        Parent parent = m.getParent();
        if (parent != null) {
            validateStringNotEmpty(
                    "parent.groupId", problems, Severity.FATAL, Version.BASE, parent.getGroupId(), parent);

            validateStringNotEmpty(
                    "parent.artifactId", problems, Severity.FATAL, Version.BASE, parent.getArtifactId(), parent);

  <modelVersion>4.0.0</modelVersion>
  <parent>
    <groupId>org.apache.maven</groupId>
    <artifactId>maven</artifactId>
    <version>4.0.0-beta-1-SNAPSHOT</version>
  </parent>

  <artifactId>maven-api-impl</artifactId>
  <name>Maven API Implementation</name>