const cpuCount = os.cpus().length;

cluster.setupPrimary({
  exec: __dirname + "/index.js",
});

for (let i = 0; i < cpuCount; i++) {
  cluster.fork();
}

Symbol.iterator
Symbol.toStringTag
Symbol.toPrimitive
Symbol.asyncIterator
Symbol.hasInstance
Symbol.isConcatSpreadable
Symbol.species
Symbol.match
Symbol.matchall
Symbol.replace
Symbol.search
Symbol.split
Symbol.unscopables
Symbol.dispose

const domObserver = new MutationObserver((_mutationList, observer) => {
  const button = document.getElementById('button');

  if (button) {
    button.addEventListener('click', () => console.log('clicked!'));

		// No need to observe anymore. Clean up!
    observer.disconnect();
  }
});