'use strict';
  
const mongodb = require('mongodb');

run().catch(error => console.log('Caught', error));

async function run() {
  const uri = 'mongodb://localhost:27017,localhost:27018,localhost:27019/test?replicaSet=rs';
  const client = await mongodb.MongoClient.connect(uri, {
    useNewUrlParser: true,
    useUnifiedTopology: true
  });
  console.log('Connected');
  
  client.on('close', () => console.log('Emitted close'));
}