var main = document.getElementById('doc');
  var output1 = main.childNodes.length;
  var textNode1 = document.createTextNode('This is some text.');
  var textNode2 = document.createTextNode('This is another text.');
  main.appendChild(textNode1);
  main.appendChild(textNode2);
  var output2 = main.childNodes.length;
  main.normalize();
  var output3 = main.childNodes.length;