public function sendTransaction($transaction_id, $affiliation, $total, $tax, $shipping, $city, $region, $country)
    {
        $this->data['utmvw'] = '5.6.4dc';
        $this->data['utms'] = ++self::$RequestsForThisSession;
        $this->data['utmt'] = 'tran';
        $this->data['utmtid'] = $transaction_id;
        $this->data['utmtst'] = $affiliation;
        $this->data['utmtto'] = $total;
        $this->data['utmttx'] = $tax;
        $this->data['utmtsp'] = $shipping;
        $this->data['utmtci'] = $city;
        $this->data['utmtrg'] = $region;
        $this->data['utmtco'] = $country;
        $this->data['utmcs'] = 'UTF-8';

        $this->send();
        $this->reset();

        return $this;
    }