Marks this flow as done.

def MarkDone(self, status=None):
    """Marks this flow as done."""
    stats_collector_instance.Get().IncrementCounter(
        "flow_completions", fields=[compatibility.GetName(self.__class__)])

    # Notify our parent flow or hunt that we are done (if there's a parent flow
    # or hunt).
    if self.rdf_flow.parent_flow_id or self.rdf_flow.parent_hunt_id:
      status = rdf_flow_objects.FlowStatus(
          client_id=self.rdf_flow.client_id,
          request_id=self.rdf_flow.parent_request_id,
          response_id=self.GetNextResponseId(),
          status=rdf_flow_objects.FlowStatus.Status.OK,
          cpu_time_used=self.rdf_flow.cpu_time_used,
          network_bytes_sent=self.rdf_flow.network_bytes_sent,
          flow_id=self.rdf_flow.parent_flow_id)
      if self.rdf_flow.parent_flow_id:
        self.flow_responses.append(status)
      elif self.rdf_flow.parent_hunt_id:
        db_compat.ProcessHuntFlowDone(self.rdf_flow, status_msg=status)

    self.rdf_flow.flow_state = self.rdf_flow.FlowState.FINISHED

    if self.ShouldSendNotifications():
      self.NotifyAboutEnd()