Исходный код метода:
$this->language->load('total/sub_total');
$sub_total = $this->cart->getSubTotal();
if (isset($this->session->data['vouchers']) && $this->session->data['vouchers']) {
foreach ($this->session->data['vouchers'] as $voucher) {
$sub_total += $voucher['amount'];
}
}
$total_data[] = array(
'code' => 'sub_total',
'title' => $this->language->get('text_sub_total'),
'text' => $this->currency->format($sub_total),
'value' => $sub_total,
'sort_order' => $this->config->get('sub_total_sort_order')
);
$total += $sub_total;
