code: def _create_prefix_notification(outgoing_msg, rpc_session):
      
      assert outgoing_msg
      path = outgoing_msg.path
      assert path
      vpn_nlri = path.nlri
  
      assert path.source is not None
      if path.source != VRF_TABLE:
          # Extract relevant info for update-add/update-delete.
          params = [{ROUTE_DISTINGUISHER: outgoing_msg.route_dist,
                     PREFIX: vpn_nlri.prefix,
                     NEXT_HOP: path.nexthop,
                     VRF_RF: VrfConf.rf_2_vrf_rf(path.route_family)}]
          if path.nlri.ROUTE_FAMILY.safi not in (subaddr_family.IP_FLOWSPEC,
                                                 subaddr_family.VPN_FLOWSPEC):
              params[VPN_LABEL] = path.label_list[0]
  
          if not path.is_withdraw:
              # Create notification to NetworkController.
              rpc_msg = rpc_session.create_notification(
                  NOTIFICATION_ADD_REMOTE_PREFIX, params)
          else:
              # Create update-delete request to NetworkController.
              rpc_msg = rpc_session.create_notification(
                  NOTIFICATION_DELETE_REMOTE_PREFIX, params)
      else:
          # Extract relevant info for update-add/update-delete.
          params = [{ROUTE_DISTINGUISHER: outgoing_msg.route_dist,
                     PREFIX: vpn_nlri.prefix,
                     NEXT_HOP: path.nexthop,
                     VRF_RF: VrfConf.rf_2_vrf_rf(path.route_family),
                     ORIGIN_RD: path.origin_rd}]
          if not path.is_withdraw:
              # Create notification to NetworkController.
              rpc_msg = rpc_session.create_notification(
                  NOTIFICATION_ADD_LOCAL_PREFIX, params)
          else:
              # Create update-delete request to NetworkController.
              rpc_msg = rpc_session.create_notification(
                  NOTIFICATION_DELETE_LOCAL_PREFIX, params)
  
      return rpc_msg
docs: Constructs prefix notification with data from given outgoing message.
  
      Given RPC session is used to create RPC notification message.