<!doctype html>
<html class="a">
 <head>
  <title>element.getElementsByClassName(): adding an element</title>
  <script src="resources/common.js"></script>
 </head>
 <body class="a">
  <p id="r">FAIL (script did not run)</p>
  <script>
   var collection = document.body.getElementsByClassName("a"),
       ele = document.createElement("x-y-z")
   ele.className = "a"
   document.body.appendChild(ele) 
   t(collection, [ele])
  </script>
 </body>
</html>