de Node to add event listener to
       * @param {string} eventName Name of event
       * @param {Function} handler Listener function to add
       */
      _addEventListenerToNode(node, eventName, handler) {
        node.addEventListener(eventName, handler);
      }

      /**
       * Override point for adding custom or simulated event handling.
       *
       * @param {Node} node Node to remove event listener from
       * @param {string} eventName Name of event
       * @param {Function} handler Liste