import org.apache.maven.api.annotations.Experimental;

/**
 * Component able to contribute to Maven session user properties. This SPI component is invoked
 * very early, while there is no session created yet.
 *
 * @since 4.0.0
 */
@Experimental
@Consumer
public interface PropertyContributor extends SpiService {
    /**

/**
 * An implementation of a workspace reader that knows how to search the Maven reactor for artifacts, either as packaged
 * jar if it has been built, or only compile output directory if packaging hasn't happened yet.
 *
 */
@Named(ReactorReader.HINT)
@SessionScoped
class ReactorReader implements MavenWorkspaceReader {
    public static final String HINT = "reactor";

    }

    // ===================================================================================================
    /**
     * Helper class to traverse graph. Required to make the containing method thread-safe
     * and yet use class level data to lessen stack usage in recursion
     */
    private class ClasspathGraphVisitor {
        MetadataGraph graph;

        ClasspathContainer cpc;

        List<MetadataGraphVertex> visited;

            } catch (Exception e) {
                throw new RuntimeException("Unable to create repository", e);
            }
        } else {
            // TODO
            throw new UnsupportedOperationException("Not yet implemented");
        }
    }

        for (Plugin plugin : project.getBuild().getPlugins()) {
            for (PluginExecution execution : plugin.getExecutions()) {
                // if the phase is specified then I don't have to go fetch the plugin yet and pull it down
                // to examine the phase it is associated to.
                if (execution.getPhase() != null) {
                    Map<Integer, List<MojoExecution>> phaseBindings = mappings.get(execution.getPhase());

     */
    @Nonnull
    Optional<Path> getArtifactPath(@Nonnull Artifact artifact);

    /**
     * Gets the relative path for a locally installed artifact. Note that the artifact need not actually exist yet at
     * the returned location, the path merely indicates where the artifact would eventually be stored.
     * <p>
     * Shortcut for {@code getService(LocalArtifactManager.class).getPathForLocalArtitact(...)}.
     *

     * <p>
     * This method should be used in "early" phase of plugin execution, possibly even when plugin or mojo descriptor
     * does not exist yet. In turn, this method will not record extra information like plugin occurrence or declaration
     * location as those are not yet available.
     */
    void reportPluginValidationIssue(
            IssueLocality locality, RepositorySystemSession session, Artifact pluginArtifact, String issue);

 * @since 4.0.0
 */
@Experimental
public interface LocalRepositoryManager extends Service {

    /**
     * Gets the relative path for a locally installed artifact.
     * Note that the artifact need not actually exist yet at
     * the returned location, the path merely indicates where
     * the artifact would eventually be stored.
     *
     * @param session The session to use, must not be {@code null}.

        // We need to set the file here or the resolver will fail with an NPE, not fully equipped to deal
        // with multiple local repository implementations yet.
        artifact.setFile(artifactFile);

        return artifact;
    }

    public List<String> findVersions(Artifact artifact) {
        return Collections.emptyList();
    }

        // We need to set the file here or the resolver will fail with an NPE, not fully equipped to deal
        // with multiple local repository implementations yet.
        artifact.setFile(artifactFile);

        return artifact;
    }

    @Override
    public String getId() {
        return localRepository.getId();
    }

    @Override