public function getContacts($modifiedAfter = 0, $cursor = null, $limit = null)
    {
        $data = self::initData($modifiedAfter, $cursor, $limit);

        $contacts = Connection::sendCurlRequest(Connection::URL_CONTACTS, 'GET', $data, false, $this->apiKey)->contacts;

        $objContacts = [];

        foreach ($contacts as $c) {
            if (!empty($c->active)) {
                $objContacts[] = new Contact($c, $this->apiKey);
            }
        }

        $this->contacts = $objContacts;

        return $objContacts;
    }