text: const https = require('https');
  const crypto = require('crypto');
  const fs = require('fs');
  
  
  const start_time = new Date();
  
  function goGoogle() {
    https.request('https://google.com', function(res){
  
      res.on('data', function() {});
  
      res.on('end', function() {
  	console.log('https - google.com ', new Date() - start_time);
      });
  
      res.on('error', function(err) {
         console.log('Error ', err);
      });
  
    }).end();
  
  }
  
  function calculateHash() {
  
  
    crypto.pbkdf2('my_password',
      'salt',
      1000000,
      512,
      'sha512',
      () => {
        console.log('Kodowanie 1:', new Date() - start_time);
      }
    );
  }
  
  // #######################################################
  
  goGoogle();
  
  fs.readFile('./package.json', 'utf8', function(){
      console.log('Wczytanie pliku :', new Date() - start_time);
  });
  
  
  calculateHash();
  calculateHash();
  calculateHash();
  calculateHash();
  
  