code: function(newNode, oldNode) {
          newNode = newNode.get ? newNode.get('element') : newNode;
          oldNode = oldNode.get ? oldNode.get('element') : oldNode;
          return this.get('element').replaceChild(newNode, oldNode);
      }
docs: Wrapper for HTMLElement method.
  @method replaceChild
  @param {HTMLElement} newNode The HTMLElement to insert
  @param {HTMLElement} oldNode The HTMLElement to replace
  @return {HTMLElement} The replaced DOM element.