Method calculatePayment

public function calculatePayment($priceI, &$total)
{
    if (!isset($total['brutto'])) {
        return false;
    }
    if (isset($priceI['brutto']) && $priceI['brutto'] > 0) {
        $total['brutto'] += $priceI['brutto'];
    } else {
        if (isset($priceI['netto']) && $priceI['netto'] > 0 && isset($priceI['tax']) && $priceI['tax'] > 0) {
            $total['brutto'] += $priceI['netto'] + $priceI['tax'];
        }
    }
}