def delete(self, doc):
        if doc.id is None:
            raise DatabaseException('Document does not have id')
        if doc.sid is None:
            try:
                rs = self.db.docs.remove({'id': doc.id}, safe=True)
                assert rs['n'] == 1
            except Exception as e:
                raise DatabaseException(e)
            return None
        doc.data = None
        return self.update(doc)
def __init__(self, queue, level, formatter):
        super(QueueingLogHandler, self).__init__()
        self._queue = queue
        self.setLevel(level)
        self.setFormatter(formatter)