Node.js http.ClientRequest.writableFinished API

// NodeJS program to demonstrate the  
// request.writableFinished APi

// Importing http module
const http = require('http');

// Create an HTTP server
const server = http.createServer((req, res) => {
  res.writeHead(200, { 'Content-Type': 'text/plain' });
  res.end('okay');
});

// Now that server is running
server.listen(3000, '127.0.0.1', () => {

  // make a request
  const options = {
    port: 3000,
    host: '127.0.0.1',
    headers: {
      'Connection': 'Upgrade',
      'Upgrade': 'websocket'
    }
  };

  // getting client request
  const req = http.request(options);

  // checking if the all data has been flushed
  // by using writableFinished api
  if(req.writableFinished)
  console.log('all data has been flushed')
  else
  console.log('all data has not been flushed')

  process.exit(0)
});