protected function dispatchCollection($collection)
    {
        // find and send group variables
        $group = isset($collection['group']) ? $collection['group'] : null;
        // dispatch action dispatcher
        $content = $this->getActionDispatcher()->dispatch($collection['action'], $group);
        if (is_string($content)) {
            $this->sendContentString($content, $this->getRequest());
        }
    }