@Override
  protected Properties createConsumerConfigs() {
    Properties consumerProps = super.createConsumerConfigs();
    /*
     * Stream application tests uses string serde for both key and value.
     * The default serde for the test producer in IntegrationTestHarness uses
     * byte serde for value and string for key.
     */
    consumerProps.setProperty(KEY_DESERIALIZER_CLASS_CONFIG, STRING_DESERIALIZER);
    consumerProps.setProperty(VALUE_DESERIALIZER_CLASS_CONFIG, STRING_DESERIALIZER);

    // for every topic create a new consumer group to avoid group rebalance
    consumerProps.setProperty(GROUP_ID_CONFIG, "group" + topicConsumerMap.size());
    return consumerProps;
  }
Container for any necessary context created during runApplication. Allows tests to access objects created within
runApplication in order to do verification.
samza-test/src/test/java/org/apache/samza/test/framework/StreamApplicationIntegrationTestHarness.java