public function getUrl($email = null, array $params = [], $secure = true)
    {
        $url  = $secure ? static::SECURE_URL : static::BASE_URL;
        $url .= is_null($email)
            ? str_repeat('0', 32)
            : static::hashEmail($email);

        if ($this->hasFormat())
            $url .= ".{$this->getFormat()}";

        if ( ! empty($params))
            $url .= '?'.http_build_query($params);

        return $url;
    }