private void processMulticastRule(ForwardingObjective fwd) {
    if (fwd.nextId() == null) {
      log.error("Multicast objective does not have a next id");
      fail(fwd, ObjectiveError.BADPARAMS);
    }

    OLTPipelineGroup next = getGroupForNextObjective(fwd.nextId());

    if (next == null) {
      log.error("Group for forwarding objective missing: {}", fwd);
      fail(fwd, ObjectiveError.GROUPMISSING);
    }

    Group group = groupService.getGroup(deviceId, next.key());
    TrafficTreatment treatment = buildTreatment(Instructions.createGroup(group.id()));

    FlowRule rule =
        DefaultFlowRule.builder()
            .forDevice(deviceId)
            .forTable(0)
            .fromApp(fwd.appId())
            .makePermanent()
            .withPriority(fwd.priority())
            .withSelector(fwd.selector())
            .withTreatment(treatment)
            .build();

    FlowRuleOperations.Builder builder = FlowRuleOperations.builder();
    switch (fwd.op()) {
      case ADD:
        builder.add(rule);
        break;
      case REMOVE:
        builder.remove(rule);
        break;
      case ADD_TO_EXISTING:
      case REMOVE_FROM_EXISTING:
        break;
      default:
        log.warn("Unknown forwarding operation: {}", fwd.op());
    }

    applyFlowRules(builder, fwd);
  }
  private void applyRules(ForwardingObjective fwd, FlowRule.Builder inner, FlowRule.Builder outer) {
    FlowRuleOperations.Builder builder = FlowRuleOperations.builder();
    switch (fwd.op()) {
      case ADD:
        builder.add(inner.build()).add(outer.build());
        break;
      case REMOVE:
        builder.remove(inner.build()).remove(outer.build());
        break;
      case ADD_TO_EXISTING:
        break;
      case REMOVE_FROM_EXISTING:
        break;
      default:
        log.warn("Unknown forwarding operation: {}", fwd.op());
    }

    applyFlowRules(builder, fwd);
  }