* This method calculates the appropriate delay for the current time
     * and applies it by sleeping the current thread.
     */
    public void delayByRules() {
        final long delay = getDelay();
        if (delay > 0) {
            ThreadUtil.sleep(delay);
        }
    }

    /**
     * Calculates the delay in milliseconds based on current time and configured rules.

      implements ScheduledFuture<V> {
    @Override
    protected Future<V> delegate() {
      throw new UnsupportedOperationException("test should not care about this");
    }

    @Override
    public long getDelay(TimeUnit unit) {
      throw new UnsupportedOperationException("test should not care about this");
    }

    @Override
    public int compareTo(Delayed other) {

      implements ScheduledFuture<V> {
    @Override
    protected Future<V> delegate() {
      throw new UnsupportedOperationException("test should not care about this");
    }

    @Override
    public long getDelay(TimeUnit unit) {
      throw new UnsupportedOperationException("test should not care about this");
    }

    @Override
    public int compareTo(Delayed other) {

           * that's possible to detect in general.
           */
        }
        return cancelled;
      }

      @Override
      public long getDelay(TimeUnit unit) {
        return scheduledDelegate.getDelay(unit);
      }

      @Override
      public int compareTo(Delayed other) {
        return scheduledDelegate.compareTo(other);
      }
    }

    // TODO(diamondm) consider moving this into addPendingString so it's always in the output
    if (this instanceof ScheduledFuture) {
      return "remaining delay=[" + ((ScheduledFuture) this).getDelay(MILLISECONDS) + " ms]";
    }
    return null;
  }

  @SuppressWarnings("CatchingUnchecked") // sneaky checked exception
  private void addPendingString(StringBuilder builder) {