if (broker.getCollection(name) == null)
collection = broker.openCollection(name, Lock.WRITE_LOCK); if (collection == null)
	public boolean removeCollection(User user, String name) throws Exception {		DBBroker broker = null;		try {			broker = brokerPool.get(user);			if (broker.getCollection(name) == null)				return false;			LOG.debug("removing collection " + name);			documentCache.clear();			return broker.removeCollection(name);		} finally {			brokerPool.release(broker);		}	}