def SendReply(self, response, tag=None):
    """Allows this flow to send a message to its parent flow.

    If this flow does not have a parent, the message is ignored.

    Args:
      response: An RDFValue() instance to be sent to the parent.
      tag: If specified, tag the result with the following tag. NOTE: supported
        in REL_DB implementation only.

    Raises:
      ValueError: If responses is not of the correct type.
    """
    del tag

    if not isinstance(response, rdfvalue.RDFValue):
      raise ValueError("SendReply can only send a Semantic Value")

    # Only send the reply if we have a parent, indicated by knowing our parent's
    # request state.
    if self.runner_args.request_state.session_id:

      request_state = self.runner_args.request_state

      request_state.response_count += 1

      # Make a response message
      msg = rdf_flows.GrrMessage(
          session_id=request_state.session_id,
          request_id=request_state.id,
          response_id=request_state.response_count,
          auth_state=rdf_flows.GrrMessage.AuthorizationState.AUTHENTICATED,
          type=rdf_flows.GrrMessage.Type.MESSAGE,
          payload=response,
          args_rdf_name=response.__class__.__name__,
          args_age=int(response.age))

      # Queue the response now
      self.queue_manager.QueueResponse(msg)

      if self.runner_args.write_intermediate_results:
        self.QueueReplyForResultCollection(response)

    else:
      # Only write the reply to the collection if we are the parent flow.
      self.QueueReplyForResultCollection(response)
Allows this flow to send a message to its parent flow.

    If this flow does not have a parent, the message is ignored.

    Args:
      response: An RDFValue() instance to be sent to the parent.
      tag: If specified, tag the result with the following tag. NOTE: supported
        in REL_DB implementation only.

    Raises:
      ValueError: If responses is not of the correct type.