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

    /**
     * Unique id identifying this artifact
     */
    @Nonnull
    default String getId() {
        return getGroupId()
                + ":" + getArtifactId()
                + ":" + getExtension()