title: Hook all Fetch Api AJAX requests
body: <p>How would you hook all AJAX requests that use the Fetch Api?  Previously we could do something like this to hook all XMLHttpRequest:</p>
  
  <pre><code>(function() {
      var origOpen = XMLHttpRequest.prototype.open;
      XMLHttpRequest.prototype.open = function() {
        console.log('request started!');
        this.addEventListener('load', function() {
            console.log('request completed!');
            console.log(this.readyState); //will always be 4 (ajax is completed successfully)
            console.log(this.responseText); //whatever the response was
        });
        origOpen.apply(this, arguments);
      };
    })();
  </code></pre>
  
  <p>Or better yet, if you wanted to add to the function above, how would you hook all Fetch Api and all XMLHttpRequest AJAX requests?</p>