anchor.diff:  
   == Kafka Consumer subscriptions
   
  -Dealing with asynchronous code is usually complicated, Kafka consumers don't help.
  +Dealing with asynchronous code in tests is often painful, Kafka consumers don't help.
   
   It can take a long time for the consumer group controller to be elected, the partitions to be assigned. 
   Between the consumer bootstrap and the first messages being received,
  
positive.code: :hp-tags: java,kafka
  :sourcedir: /sources/2019-06-31-Kafka-integration-tests
  
  You're developping a Java application which uses Kafka, 
  or maybe you're programming a data processing pipeline based on Kafka Streams. How do you automate tests involving both Java code and Kafka brokers?
  
  Such an integrations should
  
  . Start Zookeeper and then Kafka
  . Send messages into Kafka so as to trigger business code
  
negative.code: Testcontainers is strongly integrated with JUnit 5, a single annotation and you're done. A JUnit 4 rule is also available.
  [source,java]
  ----
  include::{sourcedir}/src/test/java/com/github/gquintana/kafka/ContainersMessageServiceIT.java[tags=start]
  ----
  <1> Trigger Testcontainers start
  <2> Create a Kafka container. 
  