def getall(self):
        try:
            spec = {'data': {'$exists': 1}}
            fields = {'_id': 0}
            sort = [('tid', 1)]
            cur = self.db.docs.find(spec, fields, sort=sort)
        except Exception as e:
            raise DatabaseException(e)
        return [Document(**row) for row in cur]
def get_instance(
        self,
    ) -> Callable[[appengine.GetInstanceRequest], instance.Instance]:
        r"""Return a callable for the get instance method over gRPC.

        Gets instance information.

        Returns:
            Callable[[~.GetInstanceRequest],
                    ~.Instance]:
                A function that, when called, will call the underlying RPC
                on the server.
        """
        # Generate a "stub function" on-the-fly which will actually make
        # the request.
        # gRPC handles serialization and deserialization, so we just need
        # to pass in the functions for each.
        if "get_instance" not in self._stubs:
            self._stubs["get_instance"] = self.grpc_channel.unary_unary(
                "/google.appengine.v1.Instances/GetInstance",
                request_serializer=appengine.GetInstanceRequest.serialize,
                response_deserializer=instance.Instance.deserialize,
            )
        return self._stubs["get_instance"]