@Override public int compareTo(Car car) { Preconditions.checkNotNull(car); Preconditions.checkState(timeElapsed != 0L, "Car didn't join the race."); Preconditions.checkState(car.getTimeElapsed() != 0L, "Car didn't join the race."); return ComparisonChain.start().compare(timeElapsed, car.getTimeElapsed()).result(); }