run the following:
```
export CONSUMER_GROUP=temp-1
export TOPICS=topic1,topic2
export ADDRS=host1:9092,host2:9092
export NUM_CONSUMERS=<number of concurrent Consumer to run>
go run multi-consumer-example.go
```

You'll find that when NUM_CONSUMERS > 1, things get really weird... tried with 30 initially, lowered to 2 to make the logs less spammy, same issue.

Only with NUM_CONSUMERS=1 does everything work