} else {
            SourceSet main = getSourceSets().getByName(SourceSet.MAIN_SOURCE_SET_NAME);
            JvmPluginsHelper.createDocumentationVariantWithArtifact(
                main.getSourcesElementsConfigurationName(),
                null,
                SOURCES,
                Collections.emptySet(),
                main.getSourcesJarTaskName(),
                main.getAllSource(),
                project

     * original source code in packaged form. Used to publish a variant with a '-sources' zip.
     *
     * @return the name of the sources elements configuration.
     * @since 6.0
     */
    String getSourcesElementsConfigurationName();

    /**
     * Determines if this source set is the main source set
     *
     * @since 6.7
     */
    static boolean isMain(SourceSet sourceSet) {

        if (sourcesElements != null) {
            return;
        }
        this.sourcesElements = JvmPluginsHelper.createDocumentationVariantWithArtifact(
            sourceSet.getSourcesElementsConfigurationName(),
            SourceSet.isMain(sourceSet) ? null : name,
            SOURCES,
            capabilities,
            sourceSet.getSourcesJarTaskName(),
            sourceSet.getAllSource(),