 {
  var el = document.createElement("foo")
  var tests = ["xmlns", "xmlns:a", "xmlnsx", "xmlns0"]
  for (var i = 0; i < tests.length; i++) {
    assert_true(el.toggleAttribute(tests[i]));
    assert_true(el.hasAttribute(tests[i]));
  }
}, "toggleAttribute should not throw even when qualifiedName starts with 'xmlns'")

// Step 4
test(function() {
  var el = document.createElement("foo")
  for (var i = 0; i < valid_names.length; i++) {
    assert_true(el.toggleAttribute(valid_names[i]))
    assert_true(el.ha