public function addItem($name, $price, $ammount = 1, $id = '-')
    {
        $this->items->push(Collection::make([
            'name'       => $name,
            'price'      => $price,
            'ammount'    => $ammount,
            'totalPrice' => number_format(bcmul($price, $ammount, $this->decimals), $this->decimals),
            'id'         => $id,
        ]));

        return $this;
    }