function clone ()

var treeView = new ui.TreeView(document.getElementById("treeView"));
treeView.width = treeView.height = ui.Unit.percentage(100);
treeView.theme = "standard";
treeView.loadOnDemand = true;

// create a tree node that will be a root in our hierarchy
var root = new ui.TreeNode("body");
root.expanded = true;

var span = new ui.TreeNode("span");
var div = new ui.TreeNode("div");
var p = new ui.TreeNode("p");

var elements = [span, div, p];
root.items.addRange(elements);

var copyCollection = root.items.clone();