* extension) or 'plugin' (follows the rules from extensions
     * defined as plugins).
     *
     * @param classLoadingStrategy a classLoadingStrategy object.
     */
    public void setClassLoadingStrategy(String classLoadingStrategy) {
        this.classLoadingStrategy = classLoadingStrategy;
    } // -- void setClassLoadingStrategy( String )

    /**
     * Set the group ID of the extension's artifact.
     *

        Set<String> providedArtifacts = Collections.emptySet();
        String classLoadingStrategy = extension.getClassLoadingStrategy();
        if (STRATEGY_PARENT_FIRST.equals(classLoadingStrategy)) {
            realm.importFrom(parentRealm, "");
        } else if (STRATEGY_PLUGIN.equals(classLoadingStrategy)) {
            coreExports.getExportedPackages().forEach((p, cl) -> realm.importFrom(cl, p));

        Set<String> providedArtifacts = Collections.emptySet();
        String classLoadingStrategy = extension.getClassLoadingStrategy();
        if (STRATEGY_PARENT_FIRST.equals(classLoadingStrategy)) {
            realm.importFrom(parentRealm, "");
        } else if (STRATEGY_PLUGIN.equals(classLoadingStrategy)) {
            coreExports.getExportedPackages().forEach((p, cl) -> realm.importFrom(cl, p));

                && !coreExtension.getClassLoadingStrategy().equals("self-first")) {
            serializer
                    .startTag(NAMESPACE, "classLoadingStrategy")
                    .text(coreExtension.getClassLoadingStrategy())
                    .endTag(NAMESPACE, "classLoadingStrategy");
        }
        serializer.endTag(NAMESPACE, tagName);
    } // -- void writeCoreExtension( CoreExtension, String, XmlSerializer )

                coreExtension.setVersion(interpolatedTrimmed(parser.nextText(), "version"));
            } else if (checkFieldWithDuplicate(parser, "classLoadingStrategy", null, parsed)) {
                coreExtension.setClassLoadingStrategy(interpolatedTrimmed(parser.nextText(), "classLoadingStrategy"));
            } else {
                checkUnknownElement(parser, strict);
            }
        }
        return coreExtension;