Weak hands cannot be planted, meager skills have no foundation. Shallow wisdom is futile, how can one hope for a good name?扰扰从役倦，屑屑身事微。少壮轻年月，迟暮惜光辉。
total = $total;
$this->subtotal = $subtotal;
$this->tax_total = $tax_total;
$this->shipping_total = $shipping_total;
$this->discount_total = $discount_total;
$this->currency = $currency;
}
public function to_array(): array {
return array(
'total' => $this->total,
'subtotal' => $this->subtotal,
'tax_total' => $this->tax_total,
'shipping_total' => $this->shipping_total,
'discount_total' => $this->discount_total,
'currency' => $this->currency,
);
}
public static function from_order( WC_Order $order ): self {
return new self(
$order->get_total(),
$order->get_subtotal(