leEvent(null);
  assert_equals(event.type, "null");
}, "type argument is null");

test(function() {
  var event = new ToggleEvent(undefined);
  assert_equals(event.type, "undefined");
}, "event type set to undefined");

test(function() {
  var event = new ToggleEvent("test");
  assert_equals(event.oldState, "");
}, "oldState has default value of empty string");

test(function() {
  var event = new ToggleEvent("test");
  assert_readonly(event, "oldState", "readonly attribute value");
}, "oldState is readonly