title: Append child same text node is not working
body: <p>I found the answer.
  <a href="https://stackoverflow.com/questions/6244985/insert-html-element-two-or-more-times-using-javascript">Insert HTML element two (or more) times using JavaScript</a></p>
  <p>But I need in depth knowledge about this. How does this happened without for loop or cloning?</p>
  <pre><code>let strong = document.createElement('strong');
  let text = document.createTextNode('text');
  strong.appendChild(text);
  
  let p = document.querySelector('p')
  p.appendChild(strong);
  
  // let anotherText = document.createTextNode('anotherText');
  // document.querySelector('strong').appendChild(anotherText)
  
  document.querySelector('strong').appendChild(text);
  </code></pre>
  <p>if you uncomment lines then <code>anotherText</code> gets added to strong tag.
  Why the last one is not working?</p>
  <p>There is some reference or what?</p>