protected Map<String, Object> readInitialQueueState(String... queueNames) {
		// No-op
		return Collections.emptyMap();
	}
Required for Kafka testing, where target topics may exist already. In that case, it is important to know the
initial offsets on the topics, so we can check that the writing has been correct
@return
spring-xd-dirt/src/test/java/org/springframework/xd/dirt/stream/AbstractSingleNodeStreamDeploymentIntegrationTests.java