Stopwatch unstartedStopwatch = Stopwatch.createUnstarted();
    assertFalse(unstartedStopwatch.isRunning());
    assertEquals(0, unstartedStopwatch.elapsed(NANOSECONDS));
  }

  public void testInitialState() {
    assertFalse(stopwatch.isRunning());
    assertEquals(0, stopwatch.elapsed(NANOSECONDS));
  }

  public void testStart() {
    assertSame(stopwatch, stopwatch.start());