protected function getParametersFile()
    {
        $file_name = $this->appDir . '/config/' . self::PARAMETERS_FILE . '.php';
        if (!file_exists($file_name)) {
            return [];
        }

        if (null === $this->parameters) {
            foreach (require($file_name) as $k => $v) {
                $this->parameters["%{$k}%"] = $v;
            }
        }
        return $this->parameters;
    }