I have following code in RegistrationController.

```
    class RegistrationsController < Devise::RegistrationsController
      def create
        super
        resource.customs_clearance_list.add(params[resource.class.name.underscore][:customs_clearances])
        resource.customs_consulting_list.add(params[resource.class.name.underscore][:customs_consultings])
        resource.transport_list.add(params[resource.class.name.underscore][:tranports])
        resource.fulfillment_list.add(params[resource.class.name.underscore][:fulfillments])
        resource.forward_freight_list.add(params[resource.class.name.underscore][:forward_freights])
        resource.cross_stock_list.add(params[resource.class.name.underscore][:cross_stocks])
        resource.export_list.add(params[resource.class.name.underscore][:exports])
        resource.shipping_list.add(params[resource.class.name.underscore][:shippings])
        resource.save
      end
    end
```

I made a PORO object with follwing code

```
    class RegistrationService
      def add!(resource, resource_params)
        resource.customs_clearance_list.add(resource_params[:customs_clearances])
        resource.customs_consulting_list.add(resource_params[:customs_consultings])
        resource.transport_list.add(resource_params[:tranports])
        resource.fulfillment_list.add(resource_params[:fulfillments])
        resource.forward_freight_list.add(resource_params[:forward_freights])
        resource.cross_stock_list.add(resource_params[:cross_stocks])
        resource.export_list.add(resource_params[:exports])
        resource.shipping_list.add(resource_params[:shippings])
        return resource
      end
    end
```

and then called the `add!` method like `RegistrationService.new.add!(resource, params[resource.class.name.underscore]).save` in controller.

But the resource is not being saved properly