We can remove "panel" from this list because the Panels are intended to be initialized with a reference to their top-level element. In the constructor, you can use `element` instead of `this.nodes.panel`, and [thanks to `view.js`, you can access it as `this.element`](https://github.com/evhan55/gaia/blob/1b0a9da5ccfe872d2876b0f7065dd3d0513eae5e/apps/clock/js/view.js#L22) in any instance method.