SandeepVattapparambil

class MyPromise {
  constructor(executor) {
    if (typeof executor !== 'function') {
      throw new Error('Executor must be a function');
    }

    // Internal state. `$state` is the state of the promise, and `$chained` is
    // an array of the functions we need to call once this promise is settled.
    this.$state = 'PENDING';
    this.$chained = [];

SandeepVattapparambil

// Create "backend" object to hold data for getters and setters on main object
const _ = Object.create( null );

Object.defineProperties(
    _,
    {
        firstname: {
            value: 'John',
            writable: true,
            enumerable: false,