let car = {
    getCost() {
        return this.value + this.value * this.runCosts / 100
    },


    "value":150,
    "runCosts":32,


    verySlowFunction() {
        for(let i=0; i<1e10; i++) {

        }
        return this.getCost();
    }
}

function cachDecorator(func) {
    let cache = new Map();

    return function(x) {
        if(cache.has(x)) {
            return cache.get(x);
        }
        let result = func.call(this, x);
        cache.set(x, result);
        return result;
    };


}


car.verySlowFunction = cachDecorator(car.verySlowFunction);

test = function() {alert(car.verySlowFunction())}