public function incr($key, $value = 1) {
        $value = (int) $value;
        try {
            $result = ($value > 1)
                ? $this->getRedis()->incrBy($key, $value)
                : $this->getRedis()->incr($key);
            if ($result !== false) {
                return $result;
            }
            throw new ImpossibleValueException();
        } catch (RedisException $ex) {
            throw new ConnectException();
        }
    }