private function mkSupportContacts() {
        $url = (!empty($this->attributes['support:url'][0])) ? $this->attributes['support:url'][0] : $this->support_url_substitute;
        $email = (!empty($this->attributes['support:email'][0])) ? $this->attributes['support:email'][0] : $this->support_email_substitute;
        return ['url'=>$url, 'email'=>$email];
    }