ocument.createElement("div");
  var attr = document.createAttribute("foo");
  assert_equals(el.setAttributeNode(attr), null);
  assert_equals(attr.ownerElement, el);
  assert_throws_dom("INUSE_ATTRIBUTE_ERR",
                  function() { other.setAttributeNode(attr) },
                  "Attribute already associated with el")
}, "If attrâ€™s element is neither null nor element, throw an InUseAttributeError.");

test(function() {
  var el = document.createElement("div");
  var attr = document.createAt