if (extensionRecord == null) {
            ClassRealm extensionRealm = classRealmManager.createExtensionRealm(plugin, toAetherArtifacts(artifacts));

            // TODO figure out how to use the same PluginDescriptor when running mojos

            PluginDescriptor pluginDescriptor = null;
            if (plugin.isExtensions() && !artifacts.isEmpty()) {
                // ignore plugin descriptor parsing errors at this point

            // the pool core size will be incremented before submitting
            // all the tasks, then the thread will block waiting for all
            // those subtasks to finish.
            // This ensures the number of running workers is no more than
            // the defined parallism, while making sure the pool will not
            // be exhausted
            //
            return new ThreadPoolExecutor(

            validProfileIds.add(id);
            return true;
        }
    }

    private boolean isValidProfileId(String id) {
        switch (id.charAt(0)) { // avoid first character that has special CLI meaning in "mvn -P xxx"
            case '+': // activate
            case '-': // deactivate
            case '!': // deactivate
            case '?': // optional
                return false;
            default: