extensions/solr/src/main/java/org/sakaiproject/nakamura/solr/ContentEventListener.java
protected void joinAll() throws InterruptedException {
		if (queues != null) {
			for (QueueManager q : queues) {
				q.getQueueDispatcher().join();
			}
		}
	}
protected void joinAll() throws InterruptedException {
		if (queues != null) {
			for (QueueManager q : queues) {
				q.getQueueDispatcher().join();
			}
		}
	}
used only for testing