public static function getConfigFile($filename)
    {
        $filename = addslashes($filename);
        if (is_file($filename)) {
            $data = str_replace("\\", "\\\\", file_get_contents($filename));
            $json = json_decode($data, true);

            if (empty($json)) {
                throw new \Exception("Config file has a json parse error, $filename");
            }

        } else {
            throw new \Exception("Config file not found, $filename");
        }
        
        return $json;
    }