}

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

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

  public void testStart_whileRunning() {
    stopwatch.start();

         * @param suffix optional suffix text
         */
        TextFragment(final String prefix, final String textStart, final String textEnd, final String suffix) {
            this.prefix = prefix;
            this.textStart = textStart == null ? StringUtil.EMPTY : textStart;
            this.textEnd = textEnd;
            this.suffix = suffix;
        }

        /**