title: What is window.Element()?
body: <p>I see the <code>Element</code> member on my <code>window</code> object (using the developer tools in both Chrome 54 and IE 11). <code>typeof window.Element</code> returns <code>function</code> yet <code>Element()</code> returns <code>Uncaught TypeError: Illegal constructor(…)</code> in Chrome.</p>
  
  <p>Moreover, <code>Object.keys(window).filter(e =&gt; e === 'Element').length</code> returns <code>0</code>.</p>
  
  <p>I'm not able to find any reference to <code>window.Element</code> on <a href="https://developer.mozilla.org/en-US/docs/Web/API/Window" rel="nofollow noreferrer">MDN</a> or <a href="http://www.w3schools.com/jsref/obj_window.asp" rel="nofollow noreferrer">w3schools</a>.</p>
  
  <p>Can anybody tell me what this function is and why it acts weird vis-a-vis the dev tools and Object.keys?</p>