What will be the output of this Node.js code snippet using a worker thread?

What will be the output of this Node.js code snippet using a worker thread?

const { Worker, isMainThread } = require('worker_threads');
if (isMainThread) {
  const worker = new Worker(__filename);
  worker.on('message', msg => console.log(msg));
} else {
  parentPort.postMessage('Hello from worker');
}