public function getAvatar() : ? string
    {
        //$this->cdn
        $cdn = \Phalcon\DI::getDefault()->getCdn() . '/avatars/';
        $avatar = $cdn . 'nopicture.png';

        if (!empty($this->profile_image)) {
            $avatar = $cdn . $this->profile_image;
        } elseif (!empty($this->profile_remote_image)) {
            $avatar = $this->profile_remote_image;
        }

        return $avatar;
    }