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

    protected String getKey(String classifier, String extension) {
        return classifier + ':' + extension;
    }

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

    @Override
    public String getArtifactId() {

        this.artifact = artifact;
    }

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

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

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

    @Override
    public String extendedToString() {

    @Nonnull
    default DependencyCoordinates create(@Nonnull Session session, Dependency dependency) {
        return create(DependencyCoordinatesFactoryRequest.build(
                session,
                dependency.getGroupId(),
                dependency.getArtifactId(),
                dependency.getVersion(),
                dependency.getClassifier(),
                null,
                dependency.getType()));
    }

    } // -- 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