}

    public String getType() {
        return type;
    }

    @Override
    public String getExtension() {
        if (extension == null) {
            return type;
        }
        return extension;
    }

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

    @Override
    public String getClassifier() {

     * ivy and the extension is xml.
     *
     * @see #getType()
     */
    @Nullable
    String getExtension();

    /**
     * Sets the extension of this artifact.
     */
    void setExtension(@Nullable String extension);

    /**
     * Returns the classifier of this artifact.
     */
    @Nullable
    String getClassifier();

    /**

     * For an artifact without an extension, this value will be an empty String.
     */
    String getExtension();

    /**
     * Sets the extension used to publish the artifact file.
     * @param extension The extension.
     */
    void setExtension(String extension);

    /**
     * The classifier used to publish the artifact file.

    }

    @Override
    public void setType(String type) {
        this.type = type;
    }

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

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

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

            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();
        if (versioning != null) {

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

    @Override
    public String getExtension() {
        return extension != null ? extension : getDefaultExtension();
    }

    protected abstract String getDefaultExtension();

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

    @Nullable
    @Override

        for (MavenArtifact artifact : publication.getAllArtifacts()) {
            SnapshotVersion sv = new SnapshotVersion();
            sv.setClassifier(artifact.getClassifier());
            sv.setExtension(artifact.getExtension());
            sv.setVersion(version);
            sv.setUpdated(versioning.getLastUpdated());

            versioning.getSnapshotVersions().add(sv);
        }

        for (MavenArtifact artifact : publication.getAllArtifacts()) {
            SnapshotVersion sv = new SnapshotVersion();
            sv.setClassifier(artifact.getClassifier());
            sv.setExtension(artifact.getExtension());
            sv.setVersion(timestampVersion);
            sv.setUpdated(versioning.getLastUpdated());

            versioning.getSnapshotVersions().add(sv);
        }

            SnapshotVersion sv = new SnapshotVersion();
            sv.setClassifier(artifact.getClassifier());
            sv.setExtension(artifact.getExtension());
            sv.setVersion(version);
            sv.setUpdated(lastUpdated);

            versions.put(getKey(sv.getClassifier(), sv.getExtension()), sv);
        }

        artifacts.clear();

        Versioning versioning = recessive.getVersioning();

        target.getVersioning().setSnapshot(snapshot);
        target.getVersioning().setLastUpdated("20200921071745");
        SnapshotVersion sv = new SnapshotVersion();
        sv.setClassifier("sources");
        sv.setExtension("jar");
        sv.setUpdated("20200710072412");
        target.getVersioning().addSnapshotVersion(sv);

        Metadata source = createMetadataFromArtifact(artifact);