test(function(){
  _StepTest.value = "13:00:00";
  _StepTest.step = "1";
  _StepTest.stepUp(2);
  assert_in_array(
    _StepTest.value,
    [
      "13:00:02",
      "13:00:02.0",
      "13:00:02.00",
      "13:00:02.000"],
    "a valid time string representing 2 seconds after 1pm");
}, "stepUp argument 2 times");
test(function(){
  _StepTest.value = "13:00:00";
  _StepTest.step = "1";
  _StepTest.stepDown(2);
  assert_in_array(
    _StepTest.value,
    [
      "12:59:58",
      "12:59:58.0",
      "12:59:5