public function src($email, $size = null, $rating = null)
    {
        if (is_null($size)) {
            $size = $this->getSize();
        }

        $size = max(1, min(512, $size));

        $this->setSize($size);

        if ( ! is_null($rating)) {
            $this->setRating($rating);
        }

        return $this->get($email);
    }