title: Object.entries() time complexity
body: <p>Does anyone know the complexity of <code>Object.entries()</code> in Javascript? Based on <a href="https://stackoverflow.com/questions/7716812/object-keys-complexity">this question</a> I'd guess at maybe <code>O(n)</code> as well if it's implemented by obtaining the keys and values as arrays then zipping them together?</p>