protected function getHandlers($key)
    {
        $handlers = array();

        // They key is expected to either be an array or
        // a callable function that returns an array
        if (isset($this->config[$key])) {
            if (is_callable($this->config[$key])) {
                $handlers = call_user_func($this->config[$key]);
            } elseif (is_array($this->config[$key])) {
                $handlers = $this->config[$key];
            }
        }
        return $handlers;
    }