d(child2);
      parent1.appendChild(child3);

      parent2.appendChild(document.createTextNode(""));

      parent1.normalize();
      parent2.normalize();

      assert_equals(Array.prototype.map.call(parent1.childNodes, function(el) {return el.length}).indexOf(0), -1, "Node.normalize removes empty text nodes");
      assert_equals(parent1.childNodes.length, 1, "Node.normalize merges text nodes in one");
      assert_equals(parent1.childNodes[0].length, 5, "test 1-2, Node.normalize merges text nodes valu