public void setDefaultPrefix(String defaultPrefix) {
		Assert.notNull(defaultPrefix, "'defaultPrefix' cannot be null");
		this.defaultPrefix = defaultPrefix.trim();
	}
Set the bus's default max consumers; can be overridden by consumer.maxConcurrency. Values less than 'concurrency'
will be coerced to be equal to concurrency.
@param defaultMaxConcurrency The default max concurrency.
spring-xd-messagebus-rabbit/src/main/java/org/springframework/xd/dirt/integration/rabbit/RabbitMessageBus.java