如何用Node.JS中的另外两个对象相减得到的数据创建一个动态对象？

const util = require('util');
const events = require('events');

class DynamicObject extends events.EventEmitter {
  constructor() {
    super();
  }
}

DynamicObject.prototype.subtract = function(obj1, obj2) {
  const result = obj1 - obj2;
  this.emit('result', result);
};

const dynamicObj = new DynamicObject();
dynamicObj.on('result', (result) => {
  console.log('计算结果为:', result);
});

const obj1 = 10;
const obj2 = 5;
dynamicObj.subtract(obj1, obj2);