in odoo 17 pos, there is a function named set_discount in models.js file , i want to add extra validation in it like this :
set_discount(discount) {
    var parsed_discount =
        typeof discount === "number"
            ? discount
            : isNaN(parseFloat(discount))
            ? 0
            : oParseFloat("" + discount);
    var disc = Math.min(Math.max(parsed_discount || 0, 0), 100);this.product.id });
    
    //here i want to get max discount from product.product
    
    //var maxDiscount = this.product.maxDiscount;
    //if(disc > maxDiscount){
        //alert("discount > max discount");
        //return;
    //}
    this.discount = disc;
    this.discountStr = "" + disc;
}how can i do this (var maxDiscount = this.product.maxDiscount;) in odoo 17 js
