</parent>
                    <artifactId>child1</artifactId>

                    <repositories>
                        <repository>
                            <id>child1-repo</id>
                            <url>https://child1.example.com/repo</url>
                        </repository>
                    </repositories>
                </project>
                """);

    /**
     * Gets the remote repositories to use.
     *
     * @return The remote repositories to use, never {@code null}.
     */
    List<RemoteRepository> getRepositories();

    /**
     * Sets the remote repositories to use. Note: When creating a request from a project, be sure to use the
     * plugin repositories and not the regular project repositories.
     *
     * @param repositories The remote repositories to use.

    public List<RemoteRepository> getRepositories() {
        return repositories;
    }

    @Override
    public DefaultPluginVersionRequest setRepositories(List<RemoteRepository> repositories) {
        if (repositories != null) {
            this.repositories = Collections.unmodifiableList(repositories);
        } else {
            this.repositories = Collections.emptyList();
        }

        return this;
    }

    @Override
    public List<ArtifactRepository> getEffectiveRepositories(List<ArtifactRepository> repositories) {
        if (repositories == null) {
            return null;
        }

        Map<String, List<ArtifactRepository>> reposByKey = new LinkedHashMap<>();

        for (ArtifactRepository repository : repositories) {
            String key = repository.getId();

    /**
     * Creates a derived session using the given remote repositories.
     *
     * @param repositories the new list of remote repositories
     * @return the derived session
     * @throws NullPointerException if {@code repositories} is null
     */
    @Nonnull
    Session withRemoteRepositories(@Nonnull List<RemoteRepository> repositories);

    /**

    /**
     * The possible merge modes for combining remote repositories.
     */
    enum RepositoryMerging {

        /**
         * The repositories declared in the POM have precedence over the repositories specified in the request.
         */
        POM_DOMINANT,

        /**
         * The repositories specified in the request have precedence over the repositories declared in the POM.
         */

    /**
     * Gets the remote repositories to use for the resolution.
     *
     * @return The remote repositories to use for the resolution, never {@code null}.
     */
    @Override
    List<ArtifactRepository> getRemoteRepositories();

    /**
     * Sets the remote repositories to use for the resolution.
     *
     * @param remoteRepositories The remote repositories to use for the resolution.

        Artifact l = createRemoteArtifact("l", "1.0-SNAPSHOT");
        deleteLocalArtifact(l);

        List<ArtifactRepository> repositories = new ArrayList<>();
        repositories.add(remoteRepository());
        repositories.add(badRemoteRepository());

        artifactResolver.resolve(l, repositories, localRepository());

        assertLocalArtifactPresent(l);
    }

    @Test

    /**
     * Resolves the main artifact of the specified plugin.
     *
     * @param plugin The plugin for which to resolve the main artifact, must not be {@code null}.
     * @param repositories The plugin repositories to use for resolving the plugin's main artifact, must not be {@code
     *            null}.
     * @param session The repository session to use for resolving the plugin's main artifact, must not be {@code null}.

 */
public interface ProjectBuildingHelper {

    /**
     * Creates the effective artifact repositories from the specified POM repositories.
     *
     * @param pomRepositories The POM repositories to create the artifact repositories from, must not be {@code null}.
     * @param externalRepositories The external (and already mirrored) repositories to merge into the result list, may
     *            be {@code null}.