code: function addEventListener (el, event, handler, capture) {
    const node = (el === window || el === document) ? el : findDOMNode(el)
    node.addEventListener(event, handler, capture)
  
    return {
      remove () {
        node.removeEventListener(event, handler, capture)
      }
    }
  }
docs: ---
  category: utilities/DOM
  ---
  Wrapper function for DOM addEventListener
  @module addEventListener
  @param {DOMNode} el - DOM node which will have the event listener attached
  @param {String} event - a string specifying the event name ('click', 'focus', etc)
  @param {Function} handler - function to run when event occurs
  @param {Boolean} capture - should the event be executed in the capturing or bubbling phase
  @returns {Function} a method to remove the event listener