} // -- String getClassLoadingStrategy()

    /**
     * Get the group ID of the extension's artifact.
     *
     * @return String
     */
    public String getGroupId() {
        return this.groupId;
    } // -- String getGroupId()

    /**
     * Get the version of the extension.
     *
     * @return String
     */
    public String getVersion() {
        return this.version;

        return new LocalSnapshotMetadata(metadata, path, timestamp);
    }

    public Object getKey() {
        return getGroupId() + ':' + getArtifactId() + ':' + getVersion();
    }

    public static Object getKey(Artifact artifact) {
        return artifact.getGroupId() + ':' + artifact.getArtifactId() + ':' + artifact.getBaseVersion();
    }

    @Override
    protected void merge(Metadata recessive) {

        Map<String, Plugin> index = new HashMap<>();

        for (Plugin plugin : plugins) {
            if (plugin.getGroupId() == null
                    || (plugin.getGroupId() != null
                            && plugin.getGroupId().trim().isEmpty())) {
                addViolation(
                        problems,
                        Severity.FATAL,
                        Version.V20,

        return project.getArtifact().getFile();
    }

    /** {@inheritDoc} */
    @Override
    public String getGroupId() {
        return artifact.getGroupId();
    }

    /** {@inheritDoc} */
    @Override
    public String getArtifactId() {
        return artifact.getArtifactId();
    }

    /** {@inheritDoc} */
    @Override

        return false;
    }

    @Override
    public boolean storedInArtifactVersionDirectory() {
        return false;
    }

    @Override
    public String getGroupId() {
        return artifact.getGroupId();
    }

    @Override
    public String getArtifactId() {
        return artifact.getArtifactId();
    }

    @Override
    public String getBaseVersion() {

        }

        return null;
    }

    @Override
    public List<String> findVersions(Artifact artifact) {
        List<String> versions = getProjects()
                .getOrDefault(artifact.getGroupId(), Collections.emptyMap())
                .getOrDefault(artifact.getArtifactId(), Collections.emptyMap())
                .values()
                .stream()
                .map(MavenProject::getVersion)

                currentData.setGroupId(
                        currentData.getRawModel().getGroupId() == null
                                ? parentData.getGroupId()
                                : currentData.getRawModel().getGroupId());

                currentData.setVersion(
                        currentData.getRawModel().getVersion() == null

        requireNonNull(path, "path cannot be null");
        if (artifact.getGroupId().isEmpty()
                || artifact.getArtifactId().isEmpty()
                || artifact.getBaseVersion().toString().isEmpty()) {
            artifact = session.createProducedArtifact(
                    artifact.getGroupId().isEmpty() ? project.getGroupId() : artifact.getGroupId(),

        return path.toString();
    }

    private String path(Metadata metadata) {
        StringBuilder path = new StringBuilder(128);

        if (!metadata.getGroupId().isBlank()) {
            path.append(metadata.getGroupId().replace('.', '/')).append('/');
        }

        if (!metadata.getArtifactId().isBlank()) {
            path.append(metadata.getArtifactId()).append('/');
        }

                                parent.getVersion()),
                        parent.getGroupId(),
                        parent.getArtifactId(),
                        parent.getVersion());
            }

            parent.setVersion(versionRangeResult.getHighestVersion().toString());

            return resolveModel(parent.getGroupId(), parent.getArtifactId(), parent.getVersion());