App\Http\Controllers\Laralum\Laralum::isFile PHP Method

    public static function isFile($file_name)
    {
        $files = Laralum::files();
        if (in_array($file_name, $files)) {
            return true;
        } else {
            return false;
        }
    }

 public static function mustBeFile($file_name)
 {
     if (!Laralum::isFile($file_name)) {
         abort(404);
     }
 }