06. ** Mixins

function createMixins() {
    function computerQualityMixin(classToExtend) {
        classToExtend.prototype.getQuality = function () {
            return (this.processorSpeed + this.ram + this.hardDiskSpace) / 3;
        };

        classToExtend.prototype.isFast = function () {
            return this.processorSpeed > (this.ram / 4)
        };

        classToExtend.prototype.isRoomy = function () {
            return this.hardDiskSpace > Math.floor(this.ram * this.processorSpeed)
        };
    }

    function styleMixin(classToExtend) {
        classToExtend.prototype.isFullSet = function () {
            return this.manufacturer === this.keyboard.manufacturer &&
                this.keyboard.manufacturer === this.monitor.manufacturer
        };

        classToExtend.prototype.isClassy = function () {
            const isCorrectColor = this.color === "Silver" || this.color === "Black";
            return this.battery.expectedLife >= 3 && isCorrectColor && this.weight < 3
        }
    }

    return {
        computerQualityMixin,
        styleMixin
    }
}