Major Description
This looks like it was left there by mistake:
- The consumer is thread safe but generally will be used only from within a single thread. The consumer client has no threads of it's own, all work is done in the caller's thread when calls are made on the various methods exposed.
A few paragraphs below it says:
The Kafka consumer is NOT thread-safe. All network I/O happens in the thread of the application making the call. It is the responsibility of the user to ensure that multi-threaded access is properly synchronized. Un-synchronized access will result in
Unknown macro: {@link ConcurrentModificationException}.
This matches what the code does, so the former quoted section should probably be deleted.