* @throws IllegalStateException if the root directory could not be found
     * @see #getTopDirectory()
     * @see Project#getRootDirectory()
     * @see Project#isRootProject()
     */
    @Nonnull
    Path getRootDirectory();

    /**
     * Returns a proto session builder of this instance.
     */
    @Nonnull
    default Builder toBuilder() {
        try {
            return new Builder(

        assertEquals(
                RootLocator.UNABLE_TO_FIND_ROOT_PROJECT_MESSAGE,
                assertThrows(IllegalStateException.class, session::getRootDirectory)
                        .getMessage());
    }

    @Test
    void testRootDirectory() {
        RepositorySystemSession rss = new DefaultRepositorySystemSession(h -> false);

    }

    @Override
    public boolean isRootProject() {
        return getBasedir().equals(getRootDirectory());
    }

    @Override
    public Path getRootDirectory() {
        return project.getRootDirectory();
    }

    @Override
    public Optional<Project> getParent() {
        MavenProject parent = project.getParent();

        return request;
    }

    public void setUserProperties(Properties properties) {
        this.userProperties.putAll(properties);
    }

    public Path getRootDirectory() {
        return rootDirectory;
    }

    public Path getTopDirectory() {
        return topDirectory;
    }

    @Nonnull
    @Override
    public Instant getStartTime() {
        return getMavenSession().getRequest().getStartInstant();
    }

    @Override
    public Path getRootDirectory() {
        return getMavenSession().getRequest().getRootDirectory();
    }

    @Override
    public Path getTopDirectory() {
        return getMavenSession().getRequest().getTopDirectory();
    }

    @Nonnull
    @Override

/**
 * An XML reader request.
 *
 * @since 4.0.0
 */
@Experimental
@Immutable
public interface XmlReaderRequest {

    @Nullable
    Path getPath();

    @Nullable
    Path getRootDirectory();

    @Nullable
    URL getURL();

    @Nullable
    InputStream getInputStream();

    @Nullable
    Reader getReader();

    @Nullable
    Transformer getTransformer();

                return Collections.emptyList();
            }

            throw e;
        }
    }

    private File getRootProject(MavenExecutionRequest request) {
        Path rootDirectory = request.getRootDirectory();
        if (request.getPom().getParentFile().toPath().equals(rootDirectory)) {
            return request.getPom();
        } else {
            Path rootProjectPom = modelProcessor.locateExistingPom(rootDirectory);