void assertCompletionNotExpected(long timeout) {
      Preconditions.checkArgument(timeout < expectedCompletionWaitMillis);
      assertAtLeastTimePassed(stopwatch, timeout);
      assertTimeNotPassed(stopwatch, expectedCompletionWaitMillis);
    }
  }

  private static void assertAtLeastTimePassed(Stopwatch stopwatch, long expectedMillis) {
    long elapsedMillis = stopwatch.elapsed(MILLISECONDS);
    /*