import { EventEmitter } from 'node:events';
const desk = new EventEmitter();
let total = 0;
const count = (units) => {
  total += units;
};
desk.on('checkout', count);
desk.once('ready', () => console.log('Desk ready'));
desk.emit('ready');
desk.emit('ready');
desk.emit('checkout', 2);
desk.off('checkout', count);
desk.emit('checkout', 9);
console.log(total, desk.listenerCount('checkout'));