public function random($size, $withSpecialCharacters = false)
    {
        $code = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        $code .= "abcdefghijklmnopqrstuvwxyz";
        $code .= "0123456789";

        $token = $this->generate($code, $size, $withSpecialCharacters);

        return $token;
    }