i < el.children.length; i++) {
    assert_throws_dom("INVALID_CHARACTER_ERR", function() {
      el.children[i].toggleAttribute("~", false)
    })
  }
  for (var i = 0; i < el.children.length; i++) {
    assert_throws_dom("INVALID_CHARACTER_ERR", function() {
      el.children[i].toggleAttribute("~")
    })
  }
  for (var i = 0; i < el.children.length; i++) {
    assert_throws_dom("INVALID_CHARACTER_ERR", function() {
      el.children[i].toggleAttribute("~", true)
    })
  }
}, "When qualifiedName does not