How to listen on all fetch API calls?
<p>We can modify the <code>XMLHttpRequest.prototype.open</code> to hijack all Ajax requests before. What's the equivalent if switching to the new browser's fetch API?</p>

<pre><code>const originalRequestOpen = XMLHttpRequest.prototype.open;
XMLHttpRequest.prototype.open = function() {
  this.addEventListener('load', function() {
      // do something
  });
  originalRequestOpen.apply(this, arguments);
};
</code></pre>