List<PotionEffect> effects = new ArrayList<PotionEffect>();
        effects.addAll(player.getAllActivePotionEffects());
        for (int i=0; i<effects.size(); i++) {
            PotionEffect effect = effects.get(i);
            int id = effect.getPotionID();
            if (id == 3) { // Haste
                return;
            }
        }