def search(self, regex):
        try:
            spec = {'$or': [{'data.content'    : {'$regex': regex, '$options': 'im'}},
                            {'data.description': {'$regex': regex, '$options': 'im'}}]}
            fields = {'_id': 0}
            cur = self.db.docs.find(spec, fields)
        except Exception as e:
            raise DatabaseException(e)
        return [Document(**row) for row in cur]
def get_level(self, level, queue):
		if queue == None:
			queue = []
		if level == 1:
			queue.push(self)
		else:
			if self.lchild != None:
				self.lchild.get_level(level-1, queue)
			if self.rchild != None:
				self.rchild.get_level(level-1, queue)
		return queue