* Start a separate CONSUMER receive span for each non-empty KafkaConsumer#poll() call
* One batch receive + one batch process span in spring-kafka
* Add CONSUMER receive spans to kafka-streams too
* codenarc
* code review comments
* Use kafka transactions to make spring-kafka tests more stable
* manual acks
* another approach: batch error handler that immediately recovers
* another try
* yet another try
* do nothing error handler
* spotless