code: function handleClick(event) {
    const rootNode = document;
    let element = event.target;
  
    while (element && element !== rootNode) {
      const category = element.getAttribute('data-ga-event-category');
  
      // We reach a tracking element, no need to look higher in the dom tree.
      if (category) {
        window.ga('send', {
          hitType: 'event',
          eventCategory: category,
          eventAction: element.getAttribute('data-ga-event-action'),
          eventLabel: element.getAttribute('data-ga-event-label'),
        });
        break;
      }
  
      element = element.parentNode;
    }
  }
docs: So we can write code like:  <Button ga-event-category="demo" ga-event-action="expand" > Foo </Button>