app\Billy::getContacts PHP Method

    public function getContacts()
    {
        $res = self::request("GET", "/contacts");
        $results = [];
        $i = 0;
        foreach ($res->body->contacts as $contact) {
            $results[$i]['name'] = $contact->name;
            $results[$i]['guid'] = $contact->id;
            $i++;
        }
        return $results;
    }