* @return the classifier or an empty string if none, never {@code null}
     */
    @Nonnull
    String getClassifier();

    /**
     * The version of the artifact.
     *
     * @return the version
     */
    @Nonnull
    VersionConstraint getVersion();

    /**
     * The extension of the artifact.
     *
     * @return the extension or an empty string if none, never {@code null}
     */
    @Nonnull