extend class Promise

I want to extend the 'Promise' class to follow the following structure: export default class extends Promise{ constructor(executor){ run(()=>{ super(); //executing the super constructor inside run() }); return this; } then(...args){ run(()=>{ //some adjustments for args return [login to view URL](...args) }); } wait(seconds){ //wait some time return this } } //just executes fn() and returns its value function run(fn){return fn();}