title: `insertBefore()` or `insertAfter()` deletes the element when the origin and the destination are the same
body: <p>It looks like when <code>insertBefore()</code> or <code>insertAfter()</code> has the same element as the origin and the destination, the element is deleted. Is my understanding correct?</p>
  
  <pre><code>$('#foo').insertBefore($('#foo'))
  </code></pre>
  
  <p>Is this a feature? If so, what other gotchas are there with these functions?</p>