@Override
    public ScheduledFuture<?> scheduleAtFixedRate(
        Runnable command, long initialDelay, long period, TimeUnit unit) {
      assertThat(command).isInstanceOf(WrappedRunnable.class);
      lastMethodCalled = "scheduleAtFixedRate";
      lastInitialDelay = initialDelay;
      lastDelay = period;
      lastUnit = unit;
      return null;
    }

    @Override