const Arpping = require('./index.js'); class Test { constructor() { this.arpping = new Arpping(); this.tryMe(() => this.arpping.discover(null, (err, hosts) => { if (err) return console.log(err); console.log('success'); })); } // tryMe() { // this.arpping.discover() // .then(hosts => console.log('success')) // .catch(err => console.log(err)); // } // tryMe() { // this.arpping.discover(null, (err, hosts) => { // if (err) return console.log(err); // console.log(hosts); // }); // } tryMe(callback) { callback(); } } const test = new Test();