text: "use strict";
  
  function generateBigLeaf() {
    var d = document.createElement("li");
    d.className = "leaf";
    d.textContent = new Array(10000).join("x");
    return d;
  }
  
  function generateTree() {
    var t = document.createElement("ul");
    t.style.display = "none";
    for (var i = 100; i--;) { t.appendChild(generateBigLeaf()); }
    return t;
  }
  
  document.body.appendChild(generateTree());
  
  // leak
  
  var treeRef = document.querySelector("ul");
  var leafRef = document.querySelector("li:last-child");
  