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, orchestrator):
        """
        :param orchestrator: Orchestrator instance.
        :type orchestrator: Orchestrator
        """

        # Keep a reference to the Orchestrator.
        self.__orchestrator = orchestrator

        # Keep a reference to the global RPC map (it's faster this way).
        self.__rpcMap = rpcMap

        # Check all RPC messages have been mapped at this point.
        missing = MSG_RPC_CODES.difference(self.__rpcMap.keys())
        if missing:
            msg  = "Missing RPC implementors for codes: %s"
            msg %= ", ".join(str(x) for x in sorted(missing))
            raise SyntaxError(msg)