code: def update_group_states_for_vifs(self, vifs, ack):
          
          vif_keys = [self.vif_key(vif.device_id, vif.mac_address)
                      for vif in vifs]
          self.set_fields(vif_keys, SECURITY_GROUP_ACK, ack)
docs: Updates security groups by setting the ack field