@Override
    public String getExtension() {
        return extension;
    }

    @Override
    public String getType() {
        return type;
    }

    @Override
    public String getClassifier() {
        return classifier;
    }

    @Override
    public File getFile() {
        return file;
    }

    @Override
    public Date getDate() {
        return date;
    }

        return extension;
    }

    public void setExtension(final String extension) {
        this.extension = extension;
    }

    @Override
    public String getClassifier() {
        return classifier;
    }

    public void setClassifier(final String classifier) {
        this.classifier = classifier;
    }

    @Override
    public String getDirectory() {
        if (directory == null) {

    //        setArtifactId( af.getArtifactId() );
    //        setVersion( af.getVersion() );
    //        setType( af.getType() );
    //        setScope( af.getScope() );
    //        setClassifier( af.getClassifier() );
    //        //setUri( af.getDownloadUrl() );
    //
    //        this.resolved = af.isResolved();
    //    }

    @Override
    public String toString() {

        this.extension = Strings.nullToEmpty(extension);
    }

    @Override
    public final String getClassifier() {
        return Strings.emptyToNull(classifier != null ? classifier : getDefaultClassifier());
    }

    protected abstract String getDefaultClassifier();

    @Override
    public final void setClassifier(String classifier) {
        this.classifier = Strings.nullToEmpty(classifier);
    }

    @Override

        this.directory = directory;
    }

    @Override
    public String getDirectory() {
        return directory;
    }

    public void setClassifier(String classifier) {
        this.classifier = classifier;
    }

    @Override
    public String getClassifier() {
        return classifier;
    }

    public void setPackaging(String packaging) {
        this.packaging = packaging;
    }

    @Override

        for (Artifact artifact : artifacts) {
            SnapshotVersion sv = new SnapshotVersion();
            sv.setClassifier(artifact.getClassifier());
            sv.setExtension(artifact.getExtension());
            sv.setVersion(getVersion());
            sv.setUpdated(lastUpdated);
            versions.put(getKey(sv.getClassifier(), sv.getExtension()), sv);
        }

        Versioning versioning = recessive.getVersioning();

    @Override
    public String getType() {
        return GUtil.getOrDefault(type, publishArtifact::getType);
    }

    @Override
    public String getClassifier() {
        if (classifierSet) {
            return classifier;
        }
        return publishArtifact.getClassifier();
    }

    @Override
    public File getFile() {
        return publishArtifact.getFile();
    }

    @Override

    @Override
    public void setExtension(@Nullable String extension) {
        this.extension = extension;
    }

    @Nullable
    @Override
    public String getClassifier() {
        return classifier;
    }

    @Override
    public void setClassifier(@Nullable String classifier) {
        this.classifier = classifier;
    }

    @Nullable
    @Override
    public String getUrl() {
        return url;
    }

     */
    @Nullable
    String getClassifier();

    /**
     * Sets the classifier used to publish the artifact file.
     * @param classifier The classifier.
     */
    void setClassifier(@Nullable String classifier);

    @Override
    public void setExtension(String extension) {
        throw new IllegalStateException();
    }

    @Nullable
    @Override
    public String getClassifier() {
        return classifier;
    }

    @Override
    public void setClassifier(@Nullable String classifier) {
        throw new IllegalStateException();
    }

    @Override
    public File getFile() {
        return file;
    }