if(collection != null) collection.release();
	public String createId(User user, String collName) throws EXistException {		DBBroker broker = brokerPool.get(user);		try {			Collection collection = broker.getCollection(collName);			if (collection == null)				throw new EXistException("collection " + collName						+ " not found!");			String id;			Random rand = new Random();			boolean ok;			do {				ok = true;				id = Integer.toHexString(rand.nextInt()) + ".xml";				// check if this id does already exist				if (collection.hasDocument(id))					ok = false;				if (collection.hasSubcollection(id))					ok = false;			} while (!ok);			return id;		} finally {			brokerPool.release(broker);		}	}