* @throws IllegalStateException if multiple versions of the same GA are part of the reactor
     */
    Model getRawModel(Path from, String groupId, String artifactId);

    /**
     * Locate the POM file inside the given directory.
     */
    Path locate(Path path);

    public Path getPath() {
        return path;
    }

    @Deprecated
    public void merge(File existing, File result) throws RepositoryException {
        merge(existing != null ? existing.toPath() : null, result != null ? result.toPath() : null);
    }

    @Override
    public void merge(Path existing, Path result) throws RepositoryException {
        Metadata recessive = read(existing);

        merge(recessive);

 */
package org.apache.maven.api.services.model;

import java.nio.file.Path;

import org.apache.maven.api.annotations.Nonnull;
import org.apache.maven.api.annotations.Nullable;

/**
 * Interface used to locate the root directory for a given project.
 *
 * The root locator is usually looked up from the plexus container.
 * One notable exception is the computation of the early {@code session.rootDirectory}

        this.buildNumber = buildNumber;
    }

    @Deprecated
    @Override
    public MavenMetadata setFile(File file) {
        return new RemoteSnapshotMetadata(metadata, file.toPath(), timestamp, buildNumber);
    }

    @Override
    public MavenMetadata setPath(Path path) {
        return new RemoteSnapshotMetadata(metadata, path, timestamp, buildNumber);
    }

        return artifact.getGroupId() + ':' + artifact.getArtifactId();
    }

    @Deprecated
    @Override
    public MavenMetadata setFile(File file) {
        return new VersionsMetadata(artifact, file.toPath(), timestamp);
    }

    @Override
    public MavenMetadata setPath(Path path) {
        return new VersionsMetadata(artifact, path, timestamp);
    }

    @Override
    public String getGroupId() {

        Path pomPath = pomFile.resolveSibling(relativePath).normalize();
        if (Files.isDirectory(pomPath)) {
            pomPath = context.locate(pomPath);
        }

        if (pomPath == null || !Files.isRegularFile(pomPath)) {
            return Optional.empty();
        }

        if (rootModel == null) {
            rootModel = source;
        }
    }

    private String getSource() {
        if (source == null && sourceModel != null) {
            source = ModelProblemUtils.toPath(sourceModel);
        }
        return source;
    }

    private String getModelId() {
        return ModelProblemUtils.toId(sourceModel);
    }

    public void setRootModel(Model rootModel) {

                }
            }

            @Override
            public <T> T lookup(Class<T> type, String name) {
                try {
                    return injector.getInstance(Key.of(type, name));
                } catch (DIException e) {
                    throw new MavenException("Unable to locate instance of type " + type, e);

     * TODO share with DefaultPluginMappingManager.
     */
    protected Metadata readMetadata(File mappingFile) throws RepositoryMetadataReadException {

        try (InputStream in = Files.newInputStream(mappingFile.toPath())) {
            return new Metadata(new MetadataStaxReader().read(in, false));
        } catch (FileNotFoundException e) {

     *
     * @param dir the directory to locate the pom for, never {@code null}
     * @return a {@code Source} pointing to the located pom or an empty {@code Optional} if none was found by this parser
     */
    @Nonnull
    Optional<Source> locate(@Nonnull Path dir);

    /**
     * Parse the model obtained previously by a previous call to {@link #locate(Path)}.
     *