public static function activatePlugin($configClass)
    {
        if (isset(static::$plugins[$configClass])) {
            static::$plugins[$configClass][static::IS_ACTIVE] = true;
            /** @var \Brainworxx\Krexx\Service\Plugin\PluginConfigInterface $staticPlugin */
            $staticPlugin = static::$plugins[$configClass][static::CONFIG_CLASS];
            $staticPlugin::exec();

            if (isset(Krexx::$pool)) {
                // Update stuff in the pool.
                Krexx::$pool->rewrite = static::$rewriteList;
                Krexx::$pool->eventService->register = static::$eventList;
                Krexx::$pool->messages->readHelpTexts();
            }
        }
        // No registration, no config, no plugin.
        // Do nothing.
    }